Generic Indicator Overlay on price

[monpere]

I've altered the Plot method originally from user 'Josh' s Stochastic and RSI Overlay code, to be more generic. Just add the following code to your favorite indicator to overlay it on top of price

//[Gui.Design.DisplayName(".Test")]
//Add the following method under the 'NinjaTrader.Indicator' namespace
//to override the 'Plot' method to draw the indicator overlayed on the price chart
public override void Plot(Graphics graphics, Rectangle bounds, double min, double max)
{
// Add the following variables to Initialize() method
// AutoScale = false;
// Overlay = true;
//
// The following variables can be moved out to '#region Variables'
// and corresponding '#region Properties' entries added to make these
// variables user selectable from the indicator properties sheet
// Example: for scaleHigh:
//
// Delete the scaleHigh variable from this routine.
// In '#region Variables' add the following:
// private double scaleHigh = 100;
//
// In '#region Properties' add the following:
// [Description("Scale High")]
// [Category("Parameters")]
// [Gui.Design.DisplayName("Scale High")]
// public double Scale_High
// {
// get { return scaleHigh; }
// set { scaleHigh = value; }
// }
bool drawscale = true; // Limited scale marks
double scaleHigh = 200; // Max value of indicator (100 for Stochastic, +400 for CCI, etc.)
double scaleLow = -200; // Min value of indicator (0 for Stochastic, -400 for CCI, etc.)
double upperline = 175; // Optional horizontal line 1 (80 for Stochastic)
double lowerline = -175; // Optional horizontal line 2 (20 for Stochastic)
Color uppercolor = Color.Green; // Color for line 1
Color lowercolor = Color.Green; // Color for line 2

//Draw Scale
StringFormat stringFormat = new StringFormat();
SolidBrush textBrush = new SolidBrush(Color.Black);
System.Drawing.Font textFont = new Font("Arial", 8);
double scaleRange = (scaleHigh - scaleLow);
double scaleShift = ( scaleLow < 0 ) ? -scaleLow : 0;
if(drawscale)
{
//Upper line
double line = ((upperline+scaleShift)/scaleRange)*100;
graphics.DrawLine(new Pen(uppercolor,2),bounds.X,(float)((bounds.Bottom-bounds.Y)*(1-((double)line/100))),bounds.X+bounds.Width,(float)((bounds.Botto m-bounds.Y)*(1-((double)line/100))));
graphics.DrawString(upperline.ToString(), textFont, textBrush, bounds.X, (float)((bounds.Bottom-bounds.Y)*(1-((double)line/100))),stringFormat);

//1/4 up the scale
line = (scaleRange*.75)+scaleLow;
graphics.DrawString(line.ToString(), textFont, textBrush, bounds.X, (float)((bounds.Bottom-bounds.Y)*(1-0.75)),stringFormat);

//Center Line
line = ((scaleRange/2)+scaleLow)*100;
graphics.DrawLine(new Pen(Color.DarkGray,2),bounds.X,(float)((bounds.Bot tom-bounds.Y)*0.50),bounds.X+bounds.Width,(float)((bou nds.Bottom-bounds.Y)*0.50));
graphics.DrawString(((scaleRange/2)+scaleLow).ToString(), textFont, textBrush, bounds.X, (float)((bounds.Bottom-bounds.Y)*(1-0.50)),stringFormat);

//3/4 up the scale
line = (scaleRange*.25)+scaleLow;
graphics.DrawString(line.ToString(), textFont, textBrush, bounds.X, (float)((bounds.Bottom-bounds.Y)*(1-0.25)),stringFormat);

//Lower line
line = ((lowerline+scaleShift)/scaleRange)*100;
graphics.DrawLine(new Pen(lowercolor,2),bounds.X,(float)((bounds.Bottom-bounds.Y)*(1-((double)line/100))),bounds.X+bounds.Width,(float)((bounds.Botto m-bounds.Y)*(1-((double)line/100))));
graphics.DrawString(lowerline.ToString(), textFont, textBrush, bounds.X, (float)((bounds.Bottom-bounds.Y)*(1-((double)line/100))),stringFormat);
}

//Plot Indicator
int barWidth = ChartControl.ChartStyle.GetBarPaintWidth(ChartCont rol.BarWidth);
SmoothingMode oldSmoothingMode = graphics.SmoothingMode;
GraphicsPath dpath = new GraphicsPath();
int lastX = -1;
int lastY = -1;
DataSeries series = (DataSeries) Values[0];
double seriesvalue = 0;
Gui.Chart.Plot plot = Plots[0];
for(int count = 0; count < ChartControl.BarsPainted; count++)
{
int idx = ChartControl.LastBarPainted - ChartControl.BarsPainted + 1 + count;
if (idx < 0 || idx >= Input.Count || (!ChartControl.ShowBarsRequired && idx < BarsRequired))
continue;

seriesvalue = ((series.Get(idx))+scaleShift)/scaleRange;
if (seriesvalue == 0)
continue;

int x = (int) (ChartControl.CanvasRight - ChartControl.BarMarginRight - barWidth / 2 - (ChartControl.BarsPainted - 1) * ChartControl.BarSpace + count * ChartControl.BarSpace) + 1;
int y = (int) ((bounds.Bottom-bounds.Y)*(1-seriesvalue));

if (lastX >= 0)
{
dpath.AddLine(lastX - plot.Pen.Width / 2, lastY, x - plot.Pen.Width / 2, y);
}

lastX = x;
lastY = y;
}
dpath.Reverse();

graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.DrawPath(Plots[0].Pen, dpath);
graphics.SmoothingMode = oldSmoothingMode;
}

[NinjaTrader_JoshP]

Awesome monpere. Thanks!

[sbgtrading]

Excellent! Thank you!

[sbgtrading]

Hmmm...can you give us an example of exactly where to paste your code in? I've been unable to find the right location...keep getting compile errors.

[NinjaTrader_JoshP]

It would go outside of the OnBarUpdate(), but inside the Indicator namespace.

[sbgtrading]

Hmmm...still having trouble. Can someone check the posted code to see if it's missing a "}"...or has too many of them perhaps? If not, then can someone post a test indicator that has this new code in there correctly? Thanks!

It would go outside of the OnBarUpdate(), but inside the Indicator namespace.

[NinjaTrader_JoshP]

What you probably experienced was some weirdness in the formatting when you copy and paste the code. Extra white space was added between variable names so that caused errors.

[MichaelB]

Hi Josh,
Is this a possible starting area to create a MACD Line overlay on price chart indicator?
ie, instead of having the "Diff" option set to Histogram , instead it is selected to Line to represent the value above and below the horizontal zero line ?
Thanks
Michael b

[NinjaTrader_JoshP]

For sure MichaelB, but this is beyond the level of support we can offer. Feel free to play around with the code though. I believe that is the reason why monpere released it .

[MichaelB]

Hi Josh,
Thanks
cheers
Michael B

[cachevery]

Is there a way to add alerts to those lines?

[NinjaTrader_PatrickH]

Hello cachevery,

Thank you for your post.

Unfortunately, there is no supported method to compare the price against the graphics.DrawLine() in the indicator as it is based on the Bounds of the chart window and not the price values on the chart.

[outsource]

What you probably experienced was some weirdness in the formatting when you copy and paste the code. Extra white space was added between variable names so that caused errors.

Hi there!

Is there a way to use the Plot for alert?

[NinjaTrader_ChrisL]

Hello,

Thank you for the follow-up.

Whatever meaningful values you calculate in an indicator will be stored in the Values[] array. Plots are graphical objects and have properties:
Brush, Name, PlotStyle, and Stroke.

We do have a considerable amount of control since we are scripting. You may add alerts based on any value you wish.

What would you like to accomplish in your script?

I look forward to your reply.

[outsource]

Hello,

Thank you for the follow-up.

Whatever meaningful values you calculate in an indicator will be stored in the Values[] array. Plots are graphical objects and have properties:
Brush, Name, PlotStyle, and Stroke.

We do have a considerable amount of control since we are scripting. You may add alerts based on any value you wish.

What would you like to accomplish in your script?

I look forward to your reply.

Chris, yes i would like to have an alert when the price touches the plot line.