EMA Slope Histogram - Help with Color Changes

[dwalls]

Hello,
Could someone please see if they could change the code of this indicator to make the histgram bars change color from green to red. Green if the histogram bar values are increasing and red if the histogarm bar values are decreasing.

Thanks alot,

dwalls

[anachronist]

I'd like to know how to do that too - without adding extra plot series for each color I want.

I thought the global variable BarColor sets the color of the current indicator. But it doesn't. BarColor=Color.Green always sets the color of the price bar to green, not my indicator bars.

I'd like to know how to set the width of an individual bar or point also.
-Alex

[NinjaTrader_Ben]

Hello,

Please go to: Tools>Edit NinjaScript>Indicator>VolumeUpDown, and look at the code. This default indicator is a good example on how to change the Histogram colors.

Alex - this in the way you will want to do it: with a second plot.

[anachronist]

This is the way you will want to do it: with a second plot.

OK, it seems kind of inefficient though. I'd have thought that if each price bar has its own color associated with it, then so too would each bar or point on a custom indicator would have a similar property I could set.

The same question also applies to bar width.

Also, that solution doesn't answer the question about how to make a bar plot with variable colors. Suppose for example I wanted to color the bars according to a rainbow spectrum, or temperature spectrum, depending on some calculated value. How would I do this?

-Alex

[NinjaTrader_Ben]

Hello,


Regarding the bar width you will need to do basically the same thing with a different value included after the color in Pen().

When you type in: Color.
...the editor will show you the available colors you can use. These are you choices.

[anachronist]

Um, no I don't think so. I'm now having multiple colors and widths with just one plot series. Please tell me, though, which is more efficient, computationally and memory-wise:

• Establish a plot series for every possible combination of color and line width that I intend to use (the recommended method in this thread).
• Establish just one plot series with a default color and line width, initialize DrawOnPricePanel=false, and use DrawLine() to paint over the plot with different colors and widths when needed.

DrawLine() is the workaround I am using now. Is there any disadvantage to doing it that way?

(The only downside I have observed to doing it my way is, I have to make some colors as input parameters, and all of those color names are displayed on the chart in the indicator title area.)

Alex

[NinjaTrader_JoshP]

DrawLine() can be taxing on the charting if you have it on every single bar. To remove the parameter listing from the indicator title please see this sample: http://www.ninjatrader-support.com/v...3814#post23814

[anachronist]

DrawLine() can be taxing on the charting if you have it on every single bar.

Thanks, I'll keep that in mind. On the indicator I made just now, it's looking like it's calling DrawLine() on less than 10% of the bars, so it's probably OK.
-Alex

[anachronist]

I just noticed something else.

When you type in: Color.
...the editor will show you the available colors you can use. These are your choices.

Um, the choices aren't as limited as you think. One of those choices is Color.FromArgb(), which offers over 16 million colors. If I wanted to have colors based on the result of some calculation, I'd use FromArgb(), and then I'd need a way to have a unique color on each indicator marker. The only way I can think to accomplish this is to use DrawLine() to generate my indicator.

It would be less kludgey if each marker had color and width properties that I could set. That would eliminate the need to allocate a huge number of plot series, and also eliminate the need to bog down the charting with thousands of DrawLine() objects.

Price bars have individual color properties, but not width. That should be fixed too.
-Alex

[NinjaTrader_JoshP]

Thanks for the suggestions. We will put them on the list of future considerations.

[DaveS]

Wouldn't something similar to the code in the Help system under 'Plots' do what you want?