what is C<=P-1?

What is this?
i have the code here http://www.forexfactory.com/showthread.php?t=146330 this small peice of code is under the section (COG SUM)

C<=P-1

it says Count is greater or equal to period minus one.

but i dont understand why it does this? and what exactly this does??

it is strange!

you see... you've set the Period value as 50.

That means you want the for loop to count through 50 bars ya?

what is the current bar's index? it's 0.

since you start counting from 0 instead of counting from 1. the final index after you count 50 times is actually 49.

so for that for loop. it means...

start incrementing C from 0 to 49. total number of loops = 50!!!




btw, if you want it to decrement instead, the for loop will go.


this means C will now go from 49 down to 0.

Hope this helps.

regards,
Zen

ok I understand lets say 95% now, you have got me thinking...

for
(C=0;
C<=P-1;
C++)

this is a loop like yours except it is to increment and instead of C>=0 I have C=0 (means the same)

the '0', does it mean current bar's index or is it like empy value (no bars)?

also you said 'total number of loops = 50' I dont understand this. Is it an instant answer that happens each bar or some thing else (the way you say it sounds more like it happens gradually) But then I cant picure why it would be like that. what do you mean by total number of loops?

This is how I understand it:

To get the period by which the bar is calculated (as this Is the aim)start counting from 0
count up to 49
and add 1 (this brings it back to the start because of C=0 and C<=P-1)

Am I correct?

Thank you

I'm afraid you only understood 5%. No offense... but your indicator seems to be too complicated for your programming skills. I strongly advise that you get the basics right first before moving on...

ok to help you understand what a for loop is all about. let's just forget about your indicator and work on the fundamentals first. You've got the meaning of those conditional statements within the for loop all mixed up.

let's work through a simple exercise...

e.g. I want to do a set of calculations or tasks a certain number of times, let's say 3 times. Assuming I always start counting from 0. This is good practise since arrays in MQL starts counting from 0.

consider the following code


the output of the above code would be.


let's break down the for loop conditional statements.

the first statement [int count=0] states the initial value of count at the beginning of the for loop.

the second statement [count<3] denotes the condition when the loop will continue.

the third statement [count++] is actually the last thing that'll be executed within each loop.

to put that in english means. count starts with 0. count will increment during each cycle (loop). as long as count doesn't reach a value of 3, the task (that print statement) will continue to repeat.

To be even clearer. let's go through the cycles one at a time from start to finish.

during the first cycle, count is 0. so
Print ("This is loop count number:" + count);
will give you
This is loop count number: 0

that's not all this cycle does. it ends with count++. so count becomes 1 at the start of the next cycle. the value of 1 is being put to the test with the second statement within the for loop definition. is 1<3 ? if ok? carry on then.

now we have
Print ("This is loop count number:" + count); // remember by now the count is 1.
output will be
This is loop count number: 1
again this cycle ends with count++. resulting in count becoming value of 2 at the next cycle.

count = 2 is put to the test with count < 3 again. is 2 < 3? YES!

Print ("This is loop count number:" + count); // remember by now the count is 2.
output will be
This is loop count number: 2
again this cycle ends with count++. so what is count now before the start of the next cycle? yes 3.

so upon next cycle, it goes is 3 < 3? NOPE! and the for loop ends.

The code above can also be written as


note that instead of using smaller than (<), we can use smaller than or equals to (<=). but that means we have to -1. cos we still want 2 to be a valid value of count.

There are other "unorthodox" ways of writing "for" loops. e.g.


It works exactly the same. Some may even change a "for" loop to a "while" loop.


The above code also gives the same output.

control structures or some call them cycle operators, such as for loops, while loops, case switch, etc are the bread and butter of all programmers. And it's the most basic of the basics. It is absolutely vital that you get this straighten out before going deeper.

best regards,
Zen

http://i31.photobucket.com/albums/c3.../Cycleloop.jpg

you should go read this document to know how an indicator is typically structured.

http://book.mql4.com/samples/icustom

pay particular attention to IndicatorCounted()

understanding that will help you answer your question in the previous post.

I took a brief look at your codes and there's something that bugs me...

in your (Optimise & Count) box. there's the following for loops.


any reason why you chose to break the for loop statement into different lines? and it's cycled task should be indented... so it should typically be written as.


also... if you look close enough. this for loop is redundant. since it does nothing. you start with Z=1, and that itself doesn't fit the condition of Z<=0. whatever you have inside this for loops DOESN'T get executed at all. The for loop immediately after it is wrong as well. You should look into it.

another thing... am I the only one who find your code difficult to read? The naming of those variables have no meaning to me. skimming through midway and I got pretty giddy. I understand that you're using those cos they are part of your complicated mathematical equations. But seriously, to someone else reading your code... it's rather tedious.

and please please please, practise indenting your codes. It gives your codes a lot more structure and improve readability.

regards,
Zen