Implictl convert 'Double' Error - Calc Avg

September 15th, 2016, 10:15 PM

Hi Traders,

I am using Multicharts .NET64. Unfortunately or fortunately, MC.NET supports C# and VB. The .NET version does not support easy language so I am forced to use the OO construct.

I understand programming and a bit of OO, but by far not a hard core programmer (although I pretend to be one during the day).

I am having a bit of trouble with some of the errors being thrown. Looks like a type mismatch in my coding, but I just "don't get it"..

Getting error "Cannot Implicitly convert type 'DOUBLE' to PowerLanguage.ISeries<double>'...

My intent with the signal is to create an Avg of an already calculated value.

The entire code is here with the line in question highlights in RED.

using System;
using System.Drawing;
using System.Linq;
using PowerLanguage.Function;

namespace PowerLanguage.Indicator{
public class ZJZ_OpenCloseTrend_Avg_001 : IndicatorObject {
private AverageFC m_AverageFC;

public ZJZ_OpenCloseTrend_Avg_001(object _ctx):base(_ctx)
{
// assign default values to inputs
length = 8;
}

// define the inputs
[Input]
public int length { get; set; }

private IPlotObject Open_Close_Trend;

public interface IAlert
{
bool CheckAlertLastBar { get; } // true if it is the last bar now
bool Enabled { get; } // true - if alerts are on
void Alert(); // to generate Alert with an empty text
void Alert(string Format, params object[] _args); // generate alert with message.
void Cancel(); // finish Alert generation on this bar.
}

private double SumOpenVal( int length )
{
double sumoval = 0.0;
sumoval = Bars.Open.Summation(length);
return sumoval;
}

private double SumCloseVal( int length )
{
double sumcval = 0.0;

sumcval = Bars.Close.Summation(length);
return sumcval;
}

protected override void Create() {
// create variable objects, function objects, plot objects etc.
// instantiated once
m_AverageFC = new AverageFC(this);

Open_Close_Trend = AddPlot(new PlotAttributes("OCTrend", EPlotShapes.Line, Color.Blue));

// create the ema of the trend
Open_Close_Trend = AddPlot(new PlotAttributes("AvgTrend", EPlotShapes.Line, Color.Yellow));
}
protected override void StartCalc() {
// assign inputs
}
protected override void CalcBar(){
// Avg of trend

// indicator logic
double sumopen = SumOpenVal(length);
double sumclose = SumCloseVal(length);
double trend = sumclose - sumopen;

m_AverageFC.price = trend;
m_AverageFC.length = length;
double m_avg = m_AverageFC[0];

Open_Close_Trend.Set(trend);
// dim m_trenddir string;
Open_Close_Trend.Set(m_avg);
}
}
}

TIA
JoeyZaza

September 16th, 2016, 04:42 PM

reviewing other sample codes from other indicators.. Looks like if I just eliminate the Double Type definitions, that will keep the types and assignments consistent... A bit of rework is in order..

Jura · September 17th, 2016, 02:08 AM

JoeyZaza

I am having a bit of trouble with some of the errors being thrown. Looks like a type mismatch in my coding, but I just "don't get it"..

Getting error "Cannot Implicitly convert type 'DOUBLE' to PowerLanguage.ISeries<double>'...

You're setting the `price` property of your `AverageFC` instance to a double value:

Code

double trend = sumclose - sumopen;

m_AverageFC.price = trend;

That `price` property, however, requires a series of a values to compute on, and not a single double value. This kind of makes sense when we think about what the `AverageFC` function does: computing the average from a range of different values. And to do that, it needs at least two different values to calculate the average of.

In normal English, what you're trying to do here is calculating the 8-bar average value of a single value (like 103.05, or whichever value `trend` has).

September 18th, 2016, 08:49 PM

Hi Jura,

Yes, I understand what you are saying. I am having a hard time discerning what applies to double series, etc. and the correct syntax. I have tried several permutations. As well as tried to use the same approach as the standard Mov_Avg_1_Line study. In that follows the same construct of taking multiple individual values and then average them:

....
protected override void StartCalc(){
price = Bars.Close;
m_averagefc1.price = price;
m_averagefc1.length = length;
}

protected override void CalcBar(){
m_avg.Value = m_averagefc1[0];
if (displace >= 0 || Bars.CurrentBar > Math.Abs(displace)){
Plot1.Set(displace, m_avg.Value);
if (displace <= 0){
if (this.CrossesOver(price, m_avg)){
Alerts.Alert("Price crossing over average");
}
....

Technically the Price should not care what value is given it, no? Wouldn't I be able to just pass 'trend' and 'length' to m_averagefc1.price and m_averagefc1.length respectively. Or just assign 'trend' to m_avg.Value...

September 27th, 2017, 11:17 PM

Thank you Jura.

It took a while for it all to click.. here is the (relevant) working code...

Protected Overrides Sub Create()
' create variable objects, function objects, plot objects etc.

Me.m_ocFastAvg = New AverageFC(Me)

Me.m_ocFastMA = New VariableSeries(Of Double)(Me)
End Sub

Protected Overrides Sub StartCalc() 'called once per bar

'assign inputs
Me.m_ocFastAvg.Price = m_ocFastMA
Me.m_ocFastAvg.length = FastMALen

End Sub

Protected Overrides Sub CalcBar() 'called for each tick

Dim m_ATR As Double = (Me.AverageTrueRange(Me.histLen))

Dim trend As Double = (Me._openCloseTrendFunc(0) / m_ATR)

Me.m_ocFastMA.Value = trend

Open_Close_Trend_FastMA.[Set](m_ocFastAvg(0))
End Sub
End Class
End Namespace

Best Regards,

Implictl convert 'Double' Error - Calc Avg

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Implictl convert 'Double' Error - Calc Avg