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Date/Time: Wed, 27 Nov 2024 03:43:42 +0000
[Programming Help] - trying to get started programming, problem with simple exampe (own SMA)
View Count: 342
| [2023-09-11 23:42:30] |
| User138457 - Posts: 38 |
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I tried to write my own SMA as an exercise (I know it exists as a funtion). Can anyone tell me what is going wrong with double sma; int BarIndexSize = sc.Input[0].GetInt(); sma=0.; for ( int BarIndex = sc.Index; BarIndex>sc.Index-BarIndexSize; BarIndex--) { sma=sma+(sc.Close[BarIndex]); } sma=sma/(BarIndexSize*1.f) ? It always return 0. is sth off with the indices? I skipped all the definitions here for brewety, but obv. happy to provide is necessary. TIA |
| [2023-09-18 23:53:11] |
| ForgivingComputers.com - Posts: 960 |
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Your loop starts off meeting the condition so it exits. Try adding this before the loop: if(sc.Index < BarIndexSize)
return; |
| [2023-09-21 16:55:25] |
| User138457 - Posts: 38 |
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Not helping either, curretnly the code reads double sma;
int BarIndexSize = sc.Input[0].GetInt(); sma=0.; if(sc.Index < BarIndexSize) return; //for (int BarIndex = sc.UpdateStartIndex-BarIndexSize+1; BarIndex < sc.ArraySize; BarIndex++) for ( int BarIndex = sc.ArraySize-BarIndexSize-1; BarIndex<sc.ArraySize-1; BarIndex++) { msg.Format("BarIndex = %d",BarIndex); sc.AddMessageToLog(msg,1); sma=sc.Close[BarIndex]; msg.Format("SMA = %d",sma); sc.AddMessageToLog(msg,1); } //sma=sma/(1.*BarIndexSize); msg.Format("SMA = %d",sma); sc.AddMessageToLog(msg,1); Apparently I am gravely misunderstanding sc.ArraySize and sc.Index, the (rather short) documentation did not enlight me either. Can anyone enlight me, please? |
| [2023-09-21 17:27:00] |
| ForgivingComputers.com - Posts: 960 |
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sc.Index is the current bar, sc.ArraySize is the number of bars on the chart. When recalculating the chart sc.Index starts at 0 and goes up to sc.ArraySize - 1. Since the SMA is looking back from the current bar, the size of the array is irrelevant. #include "sierrachart.h"
SCDLLName("Test SMA") SCSFExport scsf_SMA(SCStudyInterfaceRef sc) { if (sc.SetDefaults) { sc.GraphName = "Test SMA"; sc.GraphRegion = 0; sc.AutoLoop = 1; //Automatic looping is enabled. sc.Subgraph[0].Name = "SMA"; sc.Subgraph[0].DrawStyle = DRAWSTYLE_LINE; sc.Subgraph[0].PrimaryColor = RGB (0, 255, 0); sc.Input[0].Name = "Bars"; sc.Input[0].SetInt(10); return; } // Section 2 - Do data processing here double sma; double sum; int Bars = sc.Input[0].GetInt(); // We need to see at least Bars number of bars if (sc.Index < Bars) return; sum = 0.0; // Loop from current Bar back and sum close prices of each bar for (int BarIndex = sc.Index ; BarIndex > sc.Index - Bars; BarIndex--) { sum = sum + sc.Close[BarIndex]; } // Divide by Bars to get average sc.Subgraph[0][sc.Index] = sma = sum/Bars; } |
| [2023-09-21 17:50:13] |
| User138457 - Posts: 38 |
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wow, thanks for the detailed answer. I'll try that once I'm back at my Sierra Chart PC. I think I was puzzled because with alerts you count backwards from the current with negative numbers, not with positive and I was for some reason assuming it would be the same with programming. Date Time Of Last Edit: 2023-09-21 17:54:38
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| [2023-09-21 17:59:42] |
| ForgivingComputers.com - Posts: 960 |
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You are welcome. For extra credit enter 0 for the Bars setting. |
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