How to check custom calculation of previous bar

[asimbhuta]

Hey guys,

I have developed my own algorithm to plot a down or up arrow above/below the highs/lows of the current bar (upon close) if certain conditions are met.

It is possible that the next bar could also meet the same conditions, however if conditions were met on the previous bar, I would not want to plot an arrow on the new bar.

Is there a shorter way of checking if the previous bar had met the conditions or not, without having to recalculate for all conditions for the previous bar? I am looking for something along the lines of checking to see if the previous bar had an arrow associated with it or not. Is there a way of doing this?

Asim

[ninZa]

Hey guys,

I have developed my own algorithm to plot a down or up arrow above/below the highs/lows of the current bar (upon close) if certain conditions are met.

It is possible that the next bar could also meet the same conditions, however if conditions were met on the previous bar, I would not want to plot an arrow on the new bar.

Is there a shorter way of checking if the previous bar had met the conditions or not, without having to recalculate for all conditions for the previous bar? I am looking for something along the lines of checking to see if the previous bar had an arrow associated with it or not. Is there a way of doing this?

Asim

Declare global variables:

IDrawObject arrow;

When you draw an arrow, please use this tagging logic to associate the arrow to a bar:

string tag = "arrow" + CurrentBar;
arrow = DrawArrowDown(tag, AutoScale, 0, High[0], Color.Red);

or:

string tag = "arrow" + CurrentBar;
arrow = DrawArrowUp(tag, AutoScale, 0, Low[0], Color.Blue);

Then you can check if there is an arrow for the previous bar:

if (CurrentBar != 0) {

string prevTag = "arrow" + (CurrentBar - 1);

if (arrow != null && arrow.Tag == prevTag) {

// there is an arrow for the prev bar, do your stufff here

}

}

Not sure if there is a shorter solution?

Thanks.
Pi

[NinjaTrader_Bertrand]

Thanks ninZa, that's a good approach - other way I can think of would be using a bool to test if the arrow should be drawn or not and then updating the bool if the saved bar == CurrentBar + 1 so next bar.

[ninZa]

Thanks ninZa, that's a good approach - other way I can think of would be using a bool to test if the arrow should be drawn or not and then updating the bool if the saved bar == CurrentBar + 1 so next bar.

You make me think of a very simple approach, perhaps the same as yours, but should it be saved bar == CurrenBar - 1, Bertand?

Declare a global variable:

int prevBar = -100;

Every time you draw an arrow, update the prevBar as well:

DrawArrow(...);
prevBar = CurrentBar;

So, you can check if the last bar has an arrow associated with it:

if (prevBar == CurrentBar - 1) {
// the last bar has an arrow, do your stuff here
}

[NinjaTrader_Bertrand]

Thanks, you are correct - either savedBar == CurrentBar -1 or CurrentBar == savedBar + 1. Both should work fine.

[ninZa]

Thanks, you are correct - either savedBar == CurrentBar -1 or CurrentBar == savedBar + 1. Both should work fine.

I see.
Happy new year to you and all the Ninjas lol

[NinjaTrader_Bertrand]

Thanks, we wish you a Happy and successful 2015 as well!