# zero divide in my EA for charts that are not yet opened in MT4

120

Hi,

I'm trying to compare two candles. How much percentage is one candle compared to the next.

for that I am doing something Like:

open1 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_OPEN, 0);
close1 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_CLOSE, 0);
open2 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_OPEN, 1);
close2 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_CLOSE, 1);

comp1 = open1 - close1;

comp2 = open2 - close2;

percent = comp1 / comp2;

Lets say the symbol is SGDJPY. I get the following error when I run the EA.

zero divide in 'compare_bars.mq4'

But when I open the chart (at-least once) in MT4, then it works fine.

The same thing repeats when I use a new symbol say AUDHKD. Looks like market data is not downloaded for the new symbols.

Is it possible to programattically download market data if that is indeed the problem ?

2686

There is no data. Simplest thing to do is to add a test:

```open1 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_OPEN, 0);
close1 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_CLOSE, 0);
open2 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_OPEN, 1);
close2 = iMA(symbol, PERIOD_H1, 1, 0, MODE_SMA, PRICE_CLOSE, 1);

comp1 = open1 - close1;

comp2 = open2 - close2;  // this equals 0 when there is no data or in case where open2 == close2

if(comp2 != 0.0)
percent = comp1 / comp2;
else
percent = 0.0;  // or some other value meaningful for your EA
```
120

drazen64:

There is no data. Simplest thing to do is to add a test:

Thank you for the reply drazen64.

We're on the same page. I agree that that there is no data, hence the error.

The key here is the problem does not happen if I open the chart, so adding a check/test won't help as I will get the error for one symbol or the other.

My question was how do I retrieve the market info programmatically, for each symbol and time-frame of my choice. This way

I don't get the error and I don't have to manually open the charts.

2686

I see. I thought it happens when you open chart for the first time, but you are checking other currency pairs that are not in the chart you are opening.

I don't know if that could be done, but check these articles: Organizing Data Access and CopyRates()