#define GRAPH_WIDTH 750
#define GRAPH_HEIGHT 350
#include <Graphics\Graphic.mqh>
CGraphic ExtGraph;
//+------------------------------------------------------------------+
//| Script program start function |
//+------------------------------------------------------------------+
void OnStart()
{
//--- get 9 values from 0 to 8 with step 1
vector X(9,VectorArange);
Print("vector X = \n",X);
//--- for each vector value, calculate the logarithm for the expression (1 + X vector value)
X=MathLog1p(X);
Print("MathLog1p(X) = \n",X);
//--- transfer the calculated values from the vector to the array
double y_array[];
X.Swap(y_array);
//--- draw a graph of the calculated vector values
CurvePlot(y_array,clrDodgerBlue);
//--- wait for pressing the Escape or PgDn keys to delete the graph (take a screenshot) and exit
while(!IsStopped())
{
if(StopKeyPressed())
break;
Sleep(16);
}
//--- clean up
ExtGraph.Destroy();
/*
result:
vector X =
[0,1,2,3,4,5,6,7,8]
MathLog1p(X) =
[0,0.6931471805599453,1.09861228866811,1.386294361119891,1.6094379124341,1.791759469228055,1.945910149055313,2.079441541679836,2.19722457733622]
*/
}
//+------------------------------------------------------------------+
//| Fill a vector with 'value' in 'step' increments |
//+------------------------------------------------------------------+
template<typename T>
void VectorArange(vector<T> &vec,T value=0.0,T step=1.0)
{
for(ulong i=0; i<vec.Size(); i++,value+=step)
vec[i]=value;
}
//+------------------------------------------------------------------+
//| When pressing ESC, return 'true' |
//| When pressing PgDn, take a graph screenshot and return 'true' |
//| Otherwise, return 'false' |
//+------------------------------------------------------------------+
bool StopKeyPressed()
{
//--- if ESC is pressed, return 'true'
if(TerminalInfoInteger(TERMINAL_KEYSTATE_ESCAPE)!=0)
return(true);
//--- if PgDn is pressed and a graph screenshot is successfully taken, return 'true'
if(TerminalInfoInteger(TERMINAL_KEYSTATE_PAGEDOWN)!=0 && MakeAndSaveScreenshot(MQLInfoString(MQL_PROGRAM_NAME)+"_Screenshot"))
return(true);
//--- return 'false'
return(false);
}
//+------------------------------------------------------------------+
//| Create a graph object and draw a curve |
//+------------------------------------------------------------------+
void CurvePlot(double &x_array[], double &y_array[], const color colour)
{
ExtGraph.Create(ChartID(), "Graphic", 0, 0, 0, GRAPH_WIDTH, GRAPH_HEIGHT);
ExtGraph.CurveAdd(x_array, y_array, ColorToARGB(colour), CURVE_LINES);
ExtGraph.IndentUp(30);
ExtGraph.CurvePlotAll();
string text1="Press ESC to delete the graph and stop the script, or";
string text2="Press PgDn to create a screen, delete the graph and stop the script";
ExtGraph.TextAdd(54, 9, text1, ColorToARGB(clrBlack));
ExtGraph.TextAdd(54,21, text2, ColorToARGB(clrBlack));
ExtGraph.Update();
}
//+------------------------------------------------------------------+
//| Take a screenshot and save the image to a file |
//+------------------------------------------------------------------+
bool MakeAndSaveScreenshot(const string file_name)
{
string file_names[];
ResetLastError();
int selected=FileSelectDialog("Save Picture", NULL, "All files (*.*)|*.*", FSD_WRITE_FILE, file_names, file_name+".png");
if(selected<1)
{
if(selected<0)
PrintFormat("%s: FileSelectDialog() function returned error %d", __FUNCTION__, GetLastError());
return false;
}
bool res=false;
if(ChartSetInteger(0,CHART_SHOW,false))
res=ChartScreenShot(0, file_names[0], GRAPH_WIDTH, GRAPH_HEIGHT);
ChartSetInteger(0,CHART_SHOW,true);
return(res);
}
|
