Coding question

i'm still learning, so this may be a very stupid question..bear with me..

So..i always use for's with no big problem, but i only can do so with the usual format (example for(cnt=0;cnt<100;cnt++))..if i only try to throw into the mix another variable i miserably fail..here's an example i a dont know how to write correctly, i've tried multiple ways but it keeps not doing what i want it to do.

int lookback()
{
double cnt_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+1);
double cntb_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+2);
double cnt_close = iClose(NULL,Timeframe,cnt+1);
double cntb_close = iClose(NULL,Timeframe,cnt+2);

backchange=100;
for (cnt=0;cnt<backchange;cnt++)
{
if(cnt_psar<cnt_close&&cntb_psar>cntb_close){backchange=cnt;break;}
if(cnt_psar>cnt_close&&cntb_psar<cntb_close){backchange=cnt;break;}
}
}

What i would like this function to do, as u probably understood is to find the last PSAR change in the nearest past and tell me on wich bar that was.

Look at what you are doing :

double cnt_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+1) ;
double cntb_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+2) ;
double cnt_close = iClose(NULL,Timeframe,cnt+1);
double cntb_close = iClose(NULL,Timeframe,cnt+2);

You are only doing this once !!!! These statements are OUTSIDE of the FOR loop so :

a) you only ever have one set of values
b) you are using the Variable cnt BEFORE you have even assigned it a value

SO....

int lookback()
{

// define (DECALRE) your vars
int cnt,backchange;
double cnt_psar,cntb_psar,cnt_close,cntb_close;

// assign values to your vars / dont re-DECLARE it
backchange=100;


// start your for loop : which sets cnt=0 to start with

for (cnt=0;cnt<backchange;cnt++)
{

// get the values you want EACH LOOP I.E. each time cnt changes
cnt_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+1) ;
cntb_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+2) ;
cnt_close = iClose(NULL,Timeframe,cnt+1);
cntb_close = iClose(NULL,Timeframe,cnt+2);

// test your conditions
if(cnt_psar<cnt_close&&cntb_psar>cn tb_close){backchange=cnt;break;}
if(cnt_psar>cnt_close&&cntb_psar<cn tb_close){backchange=cnt;break;}

// dont bother to set backchange=cnt, I guess you have declared backchange as a global Var ... See below

} // end for loop


// Since this function is declared as int lookback() it will return an int to the //caller so......
// return from the function with the value you wanted to find?!?
return(cnt);

} // end function


HTH

hmmm...stupid me...this one works :

int lookback()
{
backchange=1;
for (cnt=0;cnt<30;cnt++)
{
double cnt_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+1);
double cntb_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+2);
double cnt_close = iClose(NULL,Timeframe,cnt+1);
double cntb_close = iClose(NULL,Timeframe,cnt+2);

if(cnt_psar>cnt_close&&cntb_psar>cntb_close){backchange++;}
if(cnt_psar<cnt_close&&cntb_psar<cntb_close){backchange++;}
if(cnt_psar<cnt_close&&cntb_psar>cntb_close){break;}
if(cnt_psar>cnt_close&&cntb_psar<cntb_close){break;}
}
}

hehe..thanks for the help mate, sometimes i do nonsense like that

for (cnt=0;cnt<30;cnt++)
{
double cnt_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+1) ;
double cntb_psar = iSAR(NULL,Timeframe,0.02,0.2,cnt+2) ;
double cnt_close = iClose(NULL,Timeframe,cnt+1);
double cntb_close = iClose(NULL,Timeframe,cnt+2);

if(cnt_psar>cnt_close&&cntb_psar>cn tb_close){backchange++;}
if(cnt_psar<cnt_close&&cntb_psar<cn tb_close){backchange++;}
if(cnt_psar<cnt_close&&cntb_psar>cn tb_close){break;}
if(cnt_psar>cnt_close&&cntb_psar<cn tb_close){break;}
}

Well it may work but think about what your doing ... You are redeclaring the double variables every time the loop runs in this example 30 times.
This is not good practice.

Declare the variables
Then use the variables

As in my example

you mean i should make the 4 doubles global?
if not that wouldnt they still be outside the "for"?

Put them above the for, underneath where you have the 'backchange=1;' declaration.

So instead of...


You'd have...

Obviously do the same for the other declarations you have in the loop.

Lux

What is the equivalent function of MathSinh() function in mql4 language?

MathSin()


https://docs.mql4.com/math/mathsin

If you mean the hyperbolic function, then no, as linked above you can see the math functions mql4 does have, but it's limited to trig, inverse trig, exp, log, power, rounding, but you can easily make your own function to do it using the exponential form of hyp sin.