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Features MQL4 Language for Newbies. Technical Indicators and Built-In Functions
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MQL4 Language for Newbies. Technical Indicators and Built-In Functions [ ru ] IntroductionThis is the third article from the series "MQL4 Language for Newbies".
In the first two articles we learned the fundamentals of MQL4, the basis of further
development. Now we will learn to use built-in functions and functions for working
with technical indicators. The latter ones will be essential in the future development
of your Expert Advisors and indicators. Besides we will see on a simple example,
how we can trace trading signals for entering the market, for you to understand,
how to use indicators correctly. And at the end of the article you will learn something
new and interesting about the language itself. Mathematical FunctionsLet us start with the most simple, but still used and helpful mathematic functions. MathAbsFunction Prototype: double MathAbs(double value) It is a very simple function, which returns the absolute value (number module).
It means, if you, for example, use it for a negative number, as a result you will
get a positive number. int a=-10; double b=-20.0; double c=7.0; a=MathAbs(a); // now a is equal to 10 b=MathAbs(b); // now b is equal to 20.0 c=MathAbs(c); // the value of c will not change, for it was positive MathCeil, MathFloor and MathRoundFunctions' prototypes: double MathCeil(double x) double MathFloor(double x) double MathRound(double value) These three functions are very much alike: all they round off a number to the whole
number. But each of them has its own peculiarity: double a; a=MathCeil(1.001); // a=2.0, even one thousandth is rounded off to a whole number a=MathCeil(1.999); // a=2.0 a=MathCeil(-1.001); // a=-1.0, it is correct, because -1.0 is more than -1.001 a=MathCeil(-1.999); // a=-1.0, it is correct, -1.0 is more than -1.999 MathFloor makes the same, as MathCeil, but quite opposite. I.e. if we need to round down a positive number, it will simply lose a fractional part: double a; a=MathFloor(1.999); // a=1.0, no matter how large the fractional part is, it will be taken away a=MathFloor(1.001); // a=1.0 a=MathFloor(-1.001); // a=-2.0, correct, because -2.0 is less than -1.001 a=MathFloor(-1.999); // a=-2.0, correct, -2.0 is less than -1.999 MathRound rounds off numbers in a familiar to us way. I.e. if a fractional part is large
(0.5 and more), it will be rounded off to 1. If the fractional part is small (less
than 0.5), it will be rounded off to 0, i.e. it will be simply omitted. Examples: double a; a=MathRound(1.1); // a=1.0, the fractional part is too small (0.1) a=MathRound(1.57); // a=2.0, the fractional part is enough to be rounded off to 1 a=MathRound(-3.1); // a=-3.0 not enough a=MathRound(-6.99); // a=-7.0 enough MathMaxMathMinFunctions' prototypes: double MathMax(double value1, double value2) double MathMin(double value1, double value2) These two functions are very much alike. They accept 2 arguments and return accordingly
the largest and the smallest one. Examples: double a; a=MathMax(50.0,1.0); // a=50.0 a=MathMin(10.0,12.0); // a=10.0 MathPowFunction prototype: double MathPow(double base, double exponent) This function allows raising a number base to the power exponent. Examples: double a; a=MathPow(5.0,2.0); // a=25.0, 5 to the power 2 a=MathPow(2.0,8.0); // a=256.0, 2 to the power 8 a=MathPow(25.0,0.5); // a=5.0, you know, a number to the power 0.5 is its square root MathSqrtFunction prototype: double MathSqrt(double x)
double a; a=MathSqrt(9.0); // a=3.0 a=MathSqrt(25.0); // a=5.0 a=MathSqrt(-256.0); // a=0.0, I explained MathLogFunction prototype: double MathLog(double x) Does anyone remember, what a logarithm is? Logarithm of a to the base b is equal to the power, to which you need to raise b, to get a. Widely used are logarithms to the bases e (Euler number) - natural logarithms (lna) and to the base 10 - common (Brigg's)
logarithm (lg a). The more information about logarithms can be found at: double a; a=MathLog(10.0); // a=2.30258509 a=MathLog(0.0); // a=-1.0, incorrect a=MathLog(-10.0); // a=-1.0, incorrect MathExpFunction prototype: double MathExp(double d) This function returns number e, raised to the power d. Many of you must have forgotten this number. double exponent=1.0; // here the degree value will be stored double result=1.0; // result, returned by the function int i=0; // number of cycle iterations while(result!=0.0) // while the result is not equal to zero (while there is no overflowing) { result=MathExp(exponent); // remember the result exponent*=10.0; // increase the degree i++; // the next iteration is over } MessageBox("i="+i); // result of the experiment The following happens: each time we try to call the function MathExp and with each iteration the degree is increased 10 times until finally we get the overflow and zero is returned. I got the following result: i=310. It means you can use as a degree numbers 1*10 to the power 309 (just imagine a number at a length of 309 digits!!). So I think you should not be afraid of the overflow. MathModFunction prototype: double MathMod(double value,double value2) This function allows finding a residue of division. For example, dividing 5 by 2
we get 2 and residue 1. The first argument value - dividend, value2 - divisor. The residue is returned. Examples: double a; a=MathExp(5,2); // a=1.0 a=MathExp(10,3); // a=1.0, correct a=MathExp(50,10); // a=0.0, divided without residue MathRand and MathSrandFunctions' prototypes: int MathRand() void MathSrand(int seed) MathRand returns one by one pseudorandom integers in the range from 0 till 32767. Here you
may have some questions: what does "pseudo" mean? What a strange range,
and what if I need from 5 to 10? Why exactly 32767? Here are the answers: int a=0; while(a<5) { MessageBox(“random=”+MathRand()); a++; } Well, the numbers are really random, but if you start the script once again, the
sequence will be always the same. It is so, because there is a number, from which
the function MathRand repulses. Let us call this number the beginning number. In order to change it, use another function - MathSrand. This function accepts a single argument - the beginning number, on which all pseudorandom
numbers will depend. Imagine that the beginning number is a fruit, from which a
tree (random numbers) will grow. On default the beginning number is 1. So, in order
to get a really random sequence, we first need to assign a unique value to the
beginning number. How can we do this? There is one more function - TimeLocal, which does not have arguments and returns the number of seconds, passed after
00:00 the 1st of January, 1970. This function suits ideally, because in most cases
we will receive a unique number. Didn't you get tangled yet? It looks like this: int a=0; MathSrand(TimeLocal()); // assign a unique value to the beginning number while(a<5) { MessageBox(“random=”+MathRand()); a++; } Now each time we will get a new sequence. Let us go on. int a=0; MathSrand(TimeLocal()); while(a<5) { MessageBox(“random=”+MathRand()%6); a++; } Please note, that we wrote MathRand()%6, not MathRand()%5 - while our range starts from zero, we need to add 1. Now suppose we need random numbers in the range from 5 to 10: MessageBox(“random=”+MathRand()%6+5); // just add the necessary shift The same is when we need to get a range with negative numbers, for example from
-5 to 5: MessageBox(“random=”+MathRand()%11-5); If you need only negative numbers, multiply the result by -1. For example we need
the range from -10 to -20: MessageBox(“random=”+(MathRand()%11+10)*(-1)); If you need to get a non-integral, for example in the range from 0.0 to 1.0 accurate
to thousandth, use the following code: MessageBox(“random=”+MathRand()%1001/1000.0); First we create a random number in the range from 0 to 1000 and then divide it by
1000.0. Note, that we must divide exactly by 1000.0 (with a floating point), not by 1000 (integer). Otherwise we get zero, because it will be rounded off. Trigonometric and arc-trigonometric functionsTrigonometric functions are mathematic functions from an angle. They are important in the analysis of periodical
processes. Very close to them are arc-trigonometric functions. More information
is here: MathSin(20.0*3.14159/180.0); I.e. 1 grade = pi / 180. It is convenient to declare and use the constant at the beginning of a program,
if you often use trigonometric functions: #define PI 3.1415926535897 MathSin, MathCos, MathTan, MathArcsin, MathArccos and MathArctanFunctions' prototypes: double MathSin(double value) double MathCos(double value) double MathTan(double x) double MathArcsin(double x) double MathArccos(double x) double MathArctan(double x) Let us dwell on the peculiarities of some functions. MathTan accepts values in the range from -263 to 263, if you exceed the limits, the number will be indefinite. MathArcsin and MathArccos accept values in the range from -1 to 1, otherwise you will get zero and the appropriate message in EA journal. MathArctan returns 0, if it accepts 0. New Functions for Displaying MessagesBy now you know only one function for displaying information - MessageBox. Now you will learn three more functions that are very much alike, but have their own peculiarities. AlertFunction prototype: void Alert(...) Displays a dialogue window containing your signals (information). At calling the function, you will hear a special signal, which can be changed or disabled in the terminal settings: Service -> Settings -> tab Events. The window will look like this:
You can change the size of the window for an easy viewing of a large amount of information.
Besides, you can always view the last callings of the function, because they are
not deleted. You can also perform several callings successively, you will get a
window with an active last signal, and you do not need to click "OK"
each time. You can use the function similar to MessageBox: Alert(“signal type:”+signalType); Alert(“random=”+MathRand()%1001); Though the intention was different. You are supposed simply to enumerate parameters
for entering, comma separated. I.e. it is like in the example above, but using
"," instead of "+". I recommend using the second variant: Alert(“signal type:”,signalType); Alert(“random=”,MathRand()%1001); CommentFunction prototype: void Comment(...) Similar function, identical in usage, displaying a message in the upper left corner
of a chart. Here you do not have to click anything to have the code performed.
Use this function, for example, for showing the current state. Example: Comment(“some usefull information”);  Function Prototype: void Print( ...) One more analogous function, displaying messages in Expert Advisors' journal: Print(“processing...”);
for(int a=0;a<100;a++) Alert("Close[",a,"]=",Close[a]); You can display maximum 64 parameters in each function. Each calling of the function Alert is also written in an Expert Advisor journal. The type double will be displayed accurate to 4 numbers after a point. Technical IndicatorsAlmost all Expert Advisors use technical indicators. If you look at a simple EA
included into the installation file (MACD Sample), you will see that it uses technical indicators. Now you will learn how to get
values of all available technical indicators. There is a correspondent function
to each technical indicator, which can count the value on any available security
and timeframe. And you do not have to bother, if this indicator is now open on
a chart or not. It does not matter. Now let us view in details the parameters of technical indicators' functions. Actually
the majority of them are repeated.
Technical indicators very often use for counting mean values on several bars. I.e. they take different prices (opening, closing, etc.) on several bars and find the mean value using a definite method. Also very often shifting is used. So among the parameters you can find the following:
The above described parameters will occur very often. So, when you see such parameters,
you should understand that this function uses mean values for the calculation of
its values. To learn, how exactly the values are calculated, and what part mean
values take in it, use the link that is after a short description of each function.
Acceleration/Deceleration (AC)The indicator Acceleration/Deceleration (AC) is used for changing the speed of price changes (acceleration, deceleration). http://ta.mql4.com/indicators/bills/acceleration_deceleration Function prototype: double iAC(string symbol, int timeframe, int shift) Parameters:
Examples of usage:
double ac; ac=iAC(0,0,0); // acceleration of the last bar on the active chart and timeframe ac=iAC(0,0,1); // acceleration of the last but one bar on the active chart and timeframe ac=iAC("GBPUSD",PERIOD_M30,0); // acceleration of the last bar on the chart GBPUSD, timeframe - 30 minutes Accumulation/Distribution (A/D)The indicator Accumulation/Distribution (A/D) is used for confirming price changes through volume calculation. double iAD(string symbol, int timeframe, int shift) Parameters:
Examples of usage:  double ad; ad=iAD(0,0,0); // accumulation on the last bar on the current chart and period ad=iAD(0,0,Bars-1); // accumulation on the first available bar, active chart and period ad=iAD("GBPUSD",PERIOD_M5,5); // accumulation on the 6th last bar on GBPUSD, period - 5 minutes AlligatorThe indicator Alligator is the combination of 3 moving averages, using fractal geometry and nonlinear dynamics.
double iAlligator( string symbol, int timeframe, int jaw_period, int jaw_shift, int teeth_period, int teeth_shift, int lips_period, int lips_shift, int ma_method, int applied_price, int mode, int shift) Parameters:
Look, what the function arguments are responsible for, when using Alligator on a
chart. Such analogy will help you: Using the parameter mode, define what should be returned:
Examples of usage: double jaw; double teeth; double lips; jaw=iAlligator(0,0,13,8,8,5,5,3,MODE_SMA,PRICE_MEDIAN,MODE_GATORJAW,0); // find the values of "jaws" (blue line) on the current chart and period. // Here simple moving average is used, price – average. Periods // of averaging for jaws, teeth and lips – 13, 8 and 8 accordingly. Shift: // 5, 5 and 3 accordingly. The value is taken for the last bar. teeth=iAlligator(“EURUSD”,PERIOD_H1,128,96,64,0,0,0,MODE_EMA,PRICE_TYPICAL,MODE_GATORTEETH,1); // find the values of "teeth" (red line) on an hour chart EURUSD. // Exponential moving average and typical price are used. // Periods of averaging: 128, 96 and 64. Shift is not used. The value // is taken for the last but one bar. lips=iAlligator(“GBPUSD”,PERIOD_D1,21,18,13,5,3,0,MODE_SMMA,PRICE_WEIGHTED,MODE_GATORLIPS,5); // find the values of "lips" (green line) on a daily chart GBPUSD. // Uses smoothed moving average and weighted close price. // Periods of averaging: 21, 18 and 13. Shift: 5, 3 and 0. The value // is taken for the 5th last bar. Average Directional Movement Index (ADX)The indicator Average Directional Movement Index (ADX) is used to determine the presence of a price trend. double iADX(string symbol,int timeframe,int period,int applied_price,int mode,int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double main; // main line double plusDi; // line +DI double minusDi; // line -DI main=iADX(0,0,3,PRICE_CLOSE,MODE_MAIN,0); // find the value of the main line on the active chart and period on the last bar. // Uses averaging on 3 bars, uses close price. plusDi=iADX(“USDCAD”,PERIOD_M1,6,PRICE_OPEN,MODE_PLUSDI,1); // find the value of line +DI on the minute chart USDCAD on the second last bar. // Uses averaging on 6 bars, uses open price. minusDi=iADX(“AUDUSD”,PERIOD_H1,10,PRICE_HIGH,MODE_MINUSDI,5); // find the value of line -DI on the hour chart AUDUSD on the 6th last bar. // Uses averaging on 10 bars, uses maximal price. Average True Range (ATR)The indicator Average True Range (ATR) is used to determine the market volatility. double iATR(string symbol,int timeframe,int period,int shift) Parameters:
Examples of usage:  double atr; atr=iATR(0,0,15,0); // volatility of the last bar on the active chart and period. // Uses 15 bars to get the mean value. atr=iATR(“EURUSD”,PERIOD_M15,5,1); // volatility of the last but one bar on a 15 minute chart EURUSD. // Uses 5 bars to get the mean value. atr=iATR(“USDCAD”,PERIOD_H1,32,0); // volatility of the last bar on an hour chart USDCAD. // Uses 32 bars to get the mean value. Awesome Oscillator (AO) by Bill WilliamsThe indicator Awesome Oscillator (AO) by Bill Williams is used to determine market moving forces. double iAO( string symbol, int timeframe, int shift) Parameters:
Examples of usage:
double ao; ao=iAO(0,0,0); // moving force of the last bar on the active chart and period ao=iAO(“EURUSD”,PERIOD_M5,0); // moving force of the last bar on 5-minute chart EURUSD ao=iAO(“EURAUD”,PERIOD_W1,1); // moving force of the last but one bar on a weekly chart EURAUD Bears PowerThe indicator Bears Power is used for estimating the balance of "bears'" power. double iBearsPower(string symbol,int timeframe,int period,int applied_price,int shift) Parameters:
Examples of usage:
double bp; bp=iBearsPower(0,0,5,PRICE_OPEN,0); // balance of the last bar on the active chart and period. Use 5 bars for averaging and opening prpice. bp=iBearsPower("EURUSD",PERIOD_M5,32,PRICE_CLOSE,1); // balance of the last but one bar on 5-minute chart EURUSD. Use 32 bars for averaging and close price. bp=iBearsPower("EURGBP",PERIOD_D1,51,PRICE_MEDIAN,0); // balance of the last bar on a daily chart EURGBP. Use 51 bars for averaging and average price. Bollinger Bands (BB)The indicator Bollinger Bands (BB) is used to determine upper and lower limits of the normal range of price fluctuations.
double iBands( string symbol, int timeframe, int period, int deviation, int bands_shift, int applied_price, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double bb; bb=iBands(0,0,20,2,0,PRICE_LOW,MODE_LOWER,0); // lower limit of the last bar on the active chart and period. // Use 20 bars for averaging, and the minimal price. // Deviation from the main line is 2, shift is not used. bb=iBands("EURUSD",PERIOD_H1,13,2,3,PRICE_HIGH,MODE_UPPER,1); // upper limit of the last but one bar on an hour chart EURUSD. // Use 13 bars for averaging, and the maximal price. // Deviation from the main line is 2, shift is 3 bars. bb=iBands("EURGBP",PERIOD_D1,21,3,4,PRICE_HIGH,MODE_UPPER,0); // upper limit of the last bar on a daily chart EURGBP. // Use 21 bars for averaging, and the maximal price. // Deviation from the main line is 2, shift is 4 bars. Bulls PowerThe indicator Bulls Power is used for estimating the balance of "bulls'" power. double iBullsPower(string symbol, int timeframe, int period, int applied_price, int shift) Parameters:
Examples of usage:
double bp; bp=iBullsPower(0,0,10,PRICE_CLOSE,1); // balance of the last but one bar on the active chart and period. Use 10 bars for averaging // and close price. bp=iBullsPower("EURGBP",PERIOD_M1,21,PRICE_HIGH,1); // balance of the last bar on a minute chart EURGBP. Use 21 bars for averaging and the maximal price. bp=iBullsPower("EURUSD",PERIOD_H1,33,PRICE_MEDIAN,0); // balance of the last bar on an hour chart EURUSD. Use 33 bars for averaging and the average price. Commodity Channel Index (CCI)The indicator Commodity Channel Index (CCI) is used for measuring the deviation of the price from its average statistical price.
double iCCI( string symbol, int timeframe, int period, int applied_price, int shift) Parameters:
Examples of usage:
double cci; cci=iCCI(0,0,14,PRICE_TYPICAL,0); // index of the last bar on the active chart and period. // Use 14 bars for finding the mean value and // typical price. cci=iCCI("EURUSD",PERIOD_M1,21,PRICE_HIGH,1); // index of the last but one bar on a minute chart EURUSD. // Use 21 bars for finding the mean value and // maximal price. cci=iCCI("EURGBP",PERIOD_D1,7,PRICE_CLOSE,0); // index of the last bar on a daily chart EURGBP. // Use 7 bars for finding the mean value and // close price. DeMarker (DeM)The indicator DeMarker (DeM) is used to forecast price turn on the basis of the price difference of past bars.
double iDeMarker( string symbol, int timeframe, int period, int shift) Parameters:
Examples of useage:
double dm; dm=iDeMarker(0,0,13,0); // DeMarker value of the last bar on the current chart and period. // Use 13 bars to find the mean value. dm=iDeMarker("EURJPY",PERIOD_H4,51,1); // DeMarker value of the last but one bar on 4-hour chart EURJPY. // Use 51 bars to find the mean value. dm=iDeMarker("USDCAD",PERIOD_M30,21,0); // DeMarker value of the last bar on 30-minutes chart USDCAD. // Use 21 bars to find the mean value. EnvelopesThe indicator Envelopes is used to determine the limits of the price fluctuations on the basis of two moving
averages. double iEnvelopes( string symbol, int timeframe, int ma_period, int ma_method, int ma_shift, int applied_price, double deviation, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double e; e=iEnvelopes(0,0,21,MODE_SMA,0,PRICE_CLOSE,0.05,MODE_LOWER,0); // lower limit of the last bar on the active chart and period. // Use 21 bars and close price for finding the value of simple moving // average. Shift is not used. Deviation from the main // line: 5%. e=iEnvelopes("EURUSD",PERIOD_H1,13,MODE_SMMA,3,PRICE_MEDIAN,0.15,MODE_UPPER,1); // upper limit of the last but one bar on an hour chart EURUSD. // Use 13 bars and average price for finding the value of smoothed moving // average. Shift: 3 bars. Deviation from the main line: 15%. e=iEnvelopes("EURAUD",PERIOD_D1,7,MODE_EMA,2,PRICE_CLOSE,0.20,MODE_LOWER,0); // lower limit of the last bar on a daily chart EURAUD. // Use 7 bars and close price for finding the value of exponential // moving average. Shift: 2 bars. Deviation from the main // line: 20%. Force Index (FRC)The indicator Force Index (FRC) is used for measuring the power of "bulls" at each rise and the power
of "bears" at each fall. double iForce( string symbol, int timeframe, int period, int ma_method, int applied_price, int shift) Parameters:
Examples of usage:
double f; f=iForce(0,0,13,MODE_SMA,PRICE_CLOSE,0); // force index of the last bar on the active chart and period. Period // of averaging: 13 bars. Method of averaging: simple moving average. // Use close price. f=iForce("EURGBP",PERIOD_M5,21,MODE_LWMA,PRICE_HIGH,1); // force index of the last but one bar on 5-minute chart EURGBP. Period // of averaging: 21 bars. Method of averaging: linearly-weighted moving average. // Use maximal price. f=iForce("EURUSD",PERIOD_M1,32,MODE_SMMA,PRICE_MEDIAN,0); // force index of the last bar on a minute chart EURUSD. Period // of averaging: 32 bars. Method of averaging: smoothed moving average. // Use average price. FractalsFractals are one of five indicators of the trading system of Bill Williams, used to detect
bottoms and tops of a price chart. Fractals appear not on all bars. So, if a fractal
did not appear on a bar, the function returns zero. double iFractals( string symbol, int timeframe, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Example of usage: double f; f=iFractals(0,0,MODE_UPPER,0); // upper fractal of the last bar on the active chart and // period. f=iFractals("USDCAD",PERIOD_M5,MODE_LOWER,1); // lower fractal of the last but one bar on 5-minute chart // USDCAD. f=iFractals("USDJPY",PERIOD_D1,MODE_UPPER,0); // upper fractal of the last bar on a daily chart USDJPY. Gator OscillatorGator Oscillator is built on tha basis of the indicator Alligator and is used for measuring the
degree of convergence or divergence of the balance lines. double iGator( string symbol, int timeframe, int jaw_period, int jaw_shift, int teeth_period, int teeth_shift, int lips_period, int lips_shift, int ma_method, int applied_price, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double g; g=iGator(0,0,13,8,8,0,0,0,MODE_SMA,PRICE_CLOSE,MODE_UPPER,0); // upper histogram of the last bar on the active chart and period. Periods of // averaging for jaw, teeth and lips accordingly: 13,8,8. Shift is not used. // For averaging use close price and the method of a simple moving average. g=iGator("EURGBP",PERIOD_M1,21,13,9,4,3,2,MODE_SMMA,PRICE_OPEN,MODE_LOWER,1); // lower histogram of the last but one bar on a minute chart EURGBP. Periods of // averaging for jaw, teeth and lips accordingly: 21,13,9. Shifts accordingly: // 4,3 and 2. For averaging use open price and the method of smoothed // moving average. g=iGator("USDCAD",PERIOD_D1,51,21,13,8,5,4,MODE_EMA,PRICE_MEDIAN,MODE_UPPER,0); // upper histogram of the last bar on a daily chart USDCAD. Periods of // averaging for jaw, teeth and lips accordingly: 51,21,13. Shifts accordingly: 8,5 and 4. // For averaging use average price and the method of exponential moving average. Ichimoku Kinko HyoThe indicator Ichimoku Kinko Hyo is used to define a trend, support and resistance levels, as well as signals to
buy and to sell. double iIchimoku( string symbol, int timeframe, int tenkan_sen, int kijun_sen, int senkou_span_b, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double i; i=iIchimoku(0,0,13,21,53,MODE_KIJUNSEN,0); // the value of the line Kijun-sen on the last bar on the current security and period. // Periods for finding mean values for Tenkan Sen, Kijun Sen and Senkou Span B // accordingly: 13,21 and 53. i=iIchimoku("EURUSD",PERIOD_M5,21,53,96,MODE_TENKANSEN,1); // the value of the line Tenkan-sen on the last but one bar on 5-minute chart EURUSD. // Periods for finding mean values for Tenkan Sen, Kijun Sen and Senkou Span B // accordingly: 21,53 and 96. i=iIchimoku("USDCAD",PERIOD_D1,3,5,9,MODE_CHINKOUSPAN,0); // the value of the line Chinkou Span on the last bar on a daily chart USDCAD. // Periods for finding mean values for Tenkan Sen, Kijun Sen and Senkou Span B // accordingly: 3,5 and 9. Market Facilitation Index (BW MFI)The indicator Market Facilitation Index (BW MFI) is used for measuring a price for one tick. double iBWMFI( string symbol, int timeframe, int shift) Parameters:
Examples of usage:
double mfi; mfi=iBWMFI(0,0,0); // index of market facilitation of the last bar on the active chart and period. mfi=iBWMFI("EURUSD",PERIOD_H1,1); // index of market facilitation of the last but one bar on an hour chart EURUSD. mfi=iBWMFI("EURGBP",PERIOD_D1,0); // index of market facilitation of the last bar on a daily chart EURGBP. MomentumThe indicator Momentum is used for measuring the amount of a price change over a period of time. double iMomentum( string symbol, int timeframe, int period, int applied_price, int shift) Parameters:
Examples of usage:
double m; m=iMomentum(0,0,12,PRICE_CLOSE,1); // momentum of the last but one bar on the active chart and period. Use // 12 bars and close price for finding a mean value. m=iMomentum("EURUSD",PERIOD_D1,21,PRICE_OPEN,0); // momentum of the last bar on a daily chart EURUSD. Use // 21 bars and open price for finding a mean value. m=iMomentum("USDCAD",PERIOD_H1,7,PRICE_MEDIAN,1); // momentum of the last but one bar on an hour chart USDCAD. Use // 7 bars and average price for finding a mean value. Money Flow Index (MFI)The indicator Money Flow Index (MFI) is used for measuring the intensity of investments. double iMFI( string symbol, int timeframe, int period, int shift) Parameters:
Examples of usage:
double mfi; iMFI(0,0,14,1); // intensity of investments of the last but one bar on the current chart and period. // Use 14 bars to find the mean value. iMFI("EURGBP",PERIOD_H4,32,0); // intensity of investments of the last bar on 4-hour chart EURGBP. // Use 32 bars to find the mean value. iMFI("EURUSD",PERIOD_W1,9,1); // intensity of investments of the last but one bar on a weekly chart EURUSD. // Use 9 bars to find the mean value. Moving Average (MA)The indicator Moving Average (MA) shows the average price for a certain period of time. double iMA( string symbol, int timeframe, int period, int ma_shift, int ma_method, int applied_price, int shift) Parameters:
Examples of usage:
double ma; ma=iMA(0,0,13,0,MODE_SMA,PRICE_CLOSE,0); // moving average of the last bar on the active chart and period. // Use 13 bars and close price for finding simple moving average. // Shift is not used. ma=iMA("GOLD",PERIOD_M15,21,6,MODE_LWMA,PRICE_LOW,1); // moving average of the last but one bar on 15-minute chart GOLD. // Use 21 bars and minimal price for finding linearly-weighted moving average. // Shift: 6 bars. ma=iMA("EURCHF",PERIOD_D1,18,4,MODE_SMMA,PRICE_TYPICAL,0); // moving average of the last bar on a daily chart EURCHF. // Use 18 bars and typical price for finding smoothed moving average. // Shift: 4 bars. Average Convergence/Divergence (MACD)The indicator Average Convergence/Divergence (MACD) is used for tracing trends based on the correlation of two moving averages. double iMACD( string symbol, int timeframe, int fast_ema_period, int slow_ema_period, int signal_period, int applied_price, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double ma; ma=iMACD(0,0,9,21,9,PRICE_CLOSE,MODE_MAIN,0); // value of the main line for the last bar on the active chart and period. // Bars, used to find mean values of a fast, slow and signal // moving average accordingly: 9,21 and 9. Use close price. ma=iMACD("EURUSD",PERIOD_H1,21,52,18,PRICE_HIGH,MODE_SIGNAL,1); // value of the signal line for the last but one bar on an hour chart EURUSD. // Bars, used to find mean values of a fast, slow and signal // moving average accordingly: 21,52 and 18. Use maximal price. ma=iMACD("USDCAD",PERIOD_D1,7,13,7,PRICE_MEDIAN,MODE_MAIN,1); // value of the main line for the last but one bar on a daily chart USDCAD. // Bars, used to find mean values of a fast, slow and signal // moving average accordingly: 7,13 and 7. Use average price. Moving Average of Oscillator (OsMA)The indicator Moving Average of Oscillator (OsMA) is used for measuring the difference between the main and the signal line of the
indicator Average Convergence/Divergence (MACD). double iOsMA( string symbol, int timeframe, int fast_ema_period, int slow_ema_period, int signal_period, int applied_price, int shift) Parameters:
Examples of usage:
double osma; osma=iOsMA(0,0,12,26,9,PRICE_CLOSE,0); // difference of the last bar on the active chart and period. Bars, used // to find mean values for the fast, slow and signal // moving average accordingly: 12,26 and 9. Use close price. osma=iOsMA("EURUSD",PERIOD_M1,7,13,6,PRICE_OPEN,1); // difference of the last but one bar on a minute chart EURUSD. Bars, used // to find mean values for the fast, slow and signal // moving average accordingly: 7,13 and 6. Use open price. osma=iOsMA("EURAUD",PERIOD_H1,21,48,18,PRICE_TYPICAL,0); // difference of the last bar on an hour chart EURAUD. Bars, used // to find mean values for the fast, slow and signal // moving average accordingly: 21,48 and 18. Use typical price. On Balance Volume (OBV)The indicator On Balance Volume (OBV) relates volume to price change, accompanying this volume. double iOBV( string symbol, int timeframe, int applied_price, int shift) Parameters:
Examples of usage:
double obv; obv=iOBV(0,0,PRICE_OPEN,0); // Balance volume of the last bar on the current chart and period. Use open price obv=iOBV("GBPCHF",PERIOD_M30,PRICE_CLOSE,1); // Balance volume of the last but one bar on 30-minutes chart GBPCHF. Use close price. obv=iOBV("GBPJPY",PERIOD_H4,PRICE_MEDIAN,0); // Balance volume of the last bar on 4-hour chart GBPJPY. Use average price. Parabolic Stop and Reverse system (Parabolic SAR)The indicator Parabolic Stop and Reverse system (Parabolic SAR) is used for analyzing trend markets and defining exit points. double iSAR( string symbol, int timeframe, double step, double maximum, int shift) Parameters:
Examples of usage:
double sar; sar=iSAR(0,0,0.02,0.2,0); // indicator value for the last bar on the current chart and period. // Step of stop level increment: 0.02. Maximal stop level: 0.2. sar=iSAR("EURUSD",PERIOD_M1,0.03,0.18,1); // indicator value for the last but one bar on a minute chart EURUSD. // Step of stop level increment: 0.03. Maximal stop level: 0.18. sar=iSAR("EURCHF",PERIOD_H1,0.01,0.15,0); // indicator value for the last bar on an hour chart EURCHF. // Step of stop level increment: 0.01. Maximal stop level: 0.15. Relative Strength Index (RSI)The indicator Relative Strength Index (RSI) is used for forecasting a price turn. double iRSI( string symbol, int timeframe, int period, int applied_price, int shift) Parameters:
Examples of usage:  double rsi; rsi=iRSI(0,0,14,PRICE_CLOSE,0); // indicator value for the last bar on the active chart and period. // Use 14 bars and close price to find the mean value. rsi=iRSI("USDCAD",PERIOD_M1,9,PRICE_OPEN,1); // indicator value for the last but one bar on a minute chart USDCAD. // Use 9 bars and close price to find the mean value. rsi=iRSI("EURAUD",PERIOD_H1,25,PRICE_TYPICAL,0); // indicator value for the last bar on an hour chart EURAUD. // Use 25 bars and typical price to find the mean value. Relative Vigor Index (RVI)The indicator Relative Vigor Index (RVI) is used to define the signals to buy and to sell. It is recommended to use this
indicator with the previous one to eliminate ambiguity. double iRVI( string symbol, int timeframe, int period, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double rvi; rvi=iRVI(0,0,12,MODE_MAIN,1); // value of the main line of the last but one bar on the active chart and period. // Use 12 bars to find the mean value. rvi=iRVI("EURUSD",PERIOD_D1,21,MODE_SIGNAL,0); // value of the signal line on the last bar on a daily chart EURUSD. // Use 21 bars to find the mean value. rvi=iRVI("GBPJPY",PERIOD_H1,19,MODE_MAIN,1); // value of the main line on the last but one bar on an hour chart GBPJPY. // Use 19 bars to find the mean value. Standard DeviationThe indicator Standard Deviation is used to measure market volatility. double iStdDev( string symbol, int timeframe, int ma_period, int ma_shift, int ma_method, int applied_price, int shift) Parameters:
Examples of usage:  double sd; sd=iStdDev(0,0,10,0,MODE_SMA,PRICE_CLOSE,1); // deviation of the last but one bar on the active chart and period. // Use 10 bars and close price to find simple // moving average. Shift is not used. sd=iStdDev("EURUSD",PERIOD_D1,21,3,MODE_SMMA,PRICE_MEDIAN,0); // deviation of the last bar on a daily chart EURUSD. // Use 21 bars and average price to find smoothed // moving average. Shift: 3 bars. sd=iStdDev("USDCAD",PERIOD_H4,17,2,MODE_EMA,PRICE_OPEN,1); // deviation of the last but one bar on 4-hour chart USDCAD. // Use 17 bars and open price to find exponential // moving average. Shift: 2 bars. Stochastic OscillatorThe indicator Stochastic Oscillator is used to define signals to buy and to sell. double iStochastic( string symbol, int timeframe, int %Kperiod, int %Dperiod, int slowing, int method, int price_field, int mode, int shift) Parameters:
Using the parameter mode define, what should be returned:
Examples of usage: double s; s=iStochastic(0,0,10,6,6,MODE_SMA,0,MODE_MAIN,0); // value of the main line for the last bar on the current chart and period. // Bars used to calculate lines %K, %D and slowing // accordingly: 10, 6 and 6. Method of averaging: simple moving average. // Use prices: Low/High. s=iStochastic("EURUSD",PERIOD_M1,6,3,3,MODE_SMMA,1,MODE_SIGNAL,1); // value of the signal line for the last but one bar on a minute chart EURUSD. // Bars used to calculate lines %K, %D and slowing // accordingly: 6, 3 and 3. Method of averaging: smoothed moving average. // Use prices: Close/Close. s=iStochastic("EURGBP",PERIOD_M5,9,7,7,MODE_EMA,0,MODE_MAIN,0); // value of the main line for the last bar on 5-minute chart EURGBP. // Bars used to calculate lines %K, %D and slowing // accordingly: 9, 7 and 7. Method of averaging: exponential moving average. // Use prices: Low/High. Williams’ Percent Range (%R)The indicator Williams’ Percent Range (%R) is used to determine whether the market is overbought/oversold. double iWPR( string symbol, int timeframe, int period, int shift) Parameters:
Examples of usage:  double wpr; wpr=iWPR(0,0,14,1); // overbought: the last but one bar on the active chart and period. // Use 14 bars to get the mean value. wpr=iWPR("USDCHF",PERIOD_D1,9,0); // overbought: The last bar on a daily chart USDCHF. // Use 9 bars to get the mean value. wpr=iWPR("GBPJPY",PERIOD_H1,23,1); // overbought: the last but one bar on an hour chart GBPJPY. // Use 23 bars to get the mean value.
The Correct Usage of Technical Indicators FunctionsFor the correct usage of these functions you must know exactly, how an indicator
is arranged and how to use it (trading signals). Of course they should be used
in your own Expert Advisors or indicators. Still, as a home task try to write a
script, which will inform about the entering points, based on the signals of any
indicator (choose yourself).
First let us declare several variables, in which we will store the values of the signal and the main line on the current and previous bar: double mainLine; double prevMainLine; double signalLine; double prevSignalLine; Now let us find the values for these variables: mainLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_MAIN,0); prevMainLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_MAIN,1); signalLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_SIGNAL,0); prevSignalLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_SIGNAL,1); You see, we restricted ourselves to the last and last but one bars. Now let us check,
if there are signals to buy and sell: if(prevMainLine<prevSignalLine && mainLine>signalLine) Alert("Signal to buy"); // if the main line was under the signal one and rised over it, // this is a signal to buy if(prevMainLine>prevSignalLine && mainLine<signalLine) Alert("Signal to sell"); // if the main line was over the signal one and fell bellow it, // this is a signal to sell We used operators of comparison and logical &&. Try to understand it properly. for(int a=0;a<100;a++) { mainLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_MAIN,a); prevMainLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_MAIN,a+1); signalLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_SIGNAL,a); prevSignalLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_SIGNAL,a+1); if(prevMainLine<prevSignalLine && mainLine>signalLine) Alert("Signal to buy"); if(prevMainLine>prevSignalLine && mainLine<signalLine) Alert("Signal to sell"); } See it? We have simply added a counter from a cycle and can check the bars. And
now for convenience instead of a hundred let us declare a constant BARS_TO_ANALYSE, which will define, how many last bars will be analyzed. Here is the final version
of the script: //+------------------------------------------------------------------+ //| showStochasticSignals.mq4 | //| Antonuk Oleg Copyright © 2007 | //| banderass@i.ua | //+------------------------------------------------------------------+ #property copyright "Antonuk Oleg Copyright © 2007" #property link "banderass@i.ua" #define BARS_TO_ANALYSE 100 //+------------------------------------------------------------------+ //| script program start function | //+------------------------------------------------------------------+ int start() { double mainLine; double prevMainLine; double signalLine; double prevSignalLine; for(int a=0;a<BARS_TO_ANALYSE;a++) { mainLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_MAIN,a); prevMainLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_MAIN,a+1); signalLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_SIGNAL,a); prevSignalLine=iStochastic(0,0,5,3,3,MODE_SMA,0,MODE_SIGNAL,a+1); if(prevMainLine<prevSignalLine && mainLine>signalLine) Alert("Signal to buy. Time: ",TimeToStr(Time[a])); if(prevMainLine>prevSignalLine && mainLine<signalLine) Alert("Signal to sell. Time: ",TimeToStr(Time[a])); } return(0); } In this script the following small code fragment must seem strange for you (if it
does, you must be a successful student): TimeToStr(Time[a]) This function accepts the amount of seconds that passed from the 1st of January
1970 and returns a string with this date. The predetermined array Time[] returns
the same number of seconds as applied to a chosen bar. Here is an ideal pair.
Something New about Variables DeclarationUsually we declare variables so: double maxPrice; double minPrice; double lastPrices[100]; int maxIndex; int minIndex; int levels[10]; Do not do so any more. Do it this way: double maxPrice, minPrice, lastPrices[100]; int maxIndex, minIndex, levels[10]; I.e. first indicate the type, and then comma separated the names of variables (arrays).
There is no difference, though we avoid unnecessary actions. The same is with initialization: int value1=10, value2=12, matrix[2][2]={1,2, 3,4}; Functions that Return Several ValuesAre there such functions?? Of course, you can write it yourself. Let us see what
you can. int func() { return(100); } And what if we need several values of different types to be returned simultaneously?
Look here: void SuperFunc(int& valueForReturn1,double& valueForReturn2,string& valueForReturn3) { valueForReturn1=100; valueForReturn2=300.0; valueForReturn3="it works!!"; } Now let us try to call this "amazing" function: int value1=0; double value2=0.0; string value3=""; SuperFunc(value1,value2,value3); MessageBox("value1="+value1+" value2="+value2+" value3="+value3); The result is the following:
This function has one common difference from simple functions: when we declare it, after the argument we put the ampersand character (&). If you do this with an argument, you can change its value inside the function, and after calling it the result will remain. Such operation with arguments is called parameter passing by reference. Thus you can return as many variables of different types as you wish. Try to omit the ampersand characters in the above code and see the result:
New Type of CommentsYou know how to comment one line: // it is a one string comment
But sometimes it is more useful to comment a certain code block, in order to disable
it temporarily. The above method is not convenient for commenting 20-30 strings.
Here we can use multi-line comments: /*
it is a multi-line comment.
Very convenient, try it.
*/
ConclusionToday you have learned a lot of new material. We have analyzed mathematic and trigonometric
functions and functions for operation with technical indicators. You saw on a simple
example how to trace trading signals correctly. And though it is not convenient
to use them in scripts, and they were created not for that purpose, soon at following
lessons you will see how to use them in your own indicators and Expert Advisors.
And then you will see how useful they actually are. Translated from Russian by MetaQuotes Software Corp.
Original article: http://articles.mql4.com/ru/456
Warning:
All rights to these materials are reserved by MetaQuotes Software Corp.
Copying or reprinting of these materials in whole or in part is prohibited.
how can i do to show an indicator that combines two or more of them?
for example: i want a new curve that shows stochastic + rsi thanks
2008.08.26 16:26 pitufogranjero
3 comments
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