SharpPlot Graphics Tools

Introduction

Included with Version 12 (32-bit Windows versions only with the Microsoft .Net Framework Version 2.0 or later installed) is the SharpPlot graphics library which is part of the RainPro graphics package..

The Version 12.0 Session includes 4 buttons which use SharpPlot to generate simple graphical pictures of the contents of the Current Object (identified by the name under or to the left of the cursor).

For example, if you have a numerical matrix in a variable called MAT, you can plot it by first positioning the cursor on the name MAT in the Session window, and then clicking one of the 4 graphical buttons in the Session toolbar.

Data Structures

The charting function can plot variables with the following data structures:

• a simple numeric vector
• a vector of simple numeric vectors
• a simple numeric matrix
• a matrix whose first row contains simple character vectors and whose other elements are simple numerics. In bar and line charts, the column headings in row 1 are used as x-axis labels.
• a matrix whose first column contains simple character vectors and whose other elements are simple numerics. In bar and line charts, the row headings in column 1 are used as legends to annotate the different series.
• a matrix whose first row and first column both contain simple character vectors and whose other elements are simple numerics. In bar and line charts, the column headings in row 1 are used as x-axis labels, and the row headings in column 1 are used as legends annotate the different series.

Examples

Bar Chart

      Wine_Prices
1961 1964 1966 
Lafite 8800 1342 1210 
Latour 15400 2357.5 4600 
Margaux 5980 672.5 920 
Mouton Rothschild 6710 713 2070 
Haut-Brion 13225 1840 1323

Line Chart

      First_Growths
1961 1964 1966 1970 1975 1976 1978 ... 
Lafite 8800 1342 1210 605 1380 2070 920 ... 
Latour 15400 2357.5 4600 2760 1552 978 1058 ... 
Margaux 5980 672.5 920 632 900 800 1208 ... 

Implementation

The SharpPlot tools are implemented by four buttons in the Session toolbar. Each button has a Select callback which runs the function ⎕SE.Chart.DoChart. This runs ⎕SE.Chart.Do which constructs and then runs a function named ⎕SE.Chart.MyChart.

⎕SE.Chart.MyChart uses an instance of the SharpPlot graphics class to produce a chart of your data, which it saves as a temporary file. It then calls the SharpPlot viewer to display the file on your screen.

SharpPlot is a library of graphical subroutines, (originally written in APL and machine-translated into C#) which is implemented as a .Net Namespace named Causeway and supplied in \bin\sharpplot.dll in the Dyalog program directory.

Notes

For further information on using SharpPlot, please see http://www.sharpplot.com/Docs.

Although ⎕SE.Chart.MyChart is overwritten by successive uses of the graphical buttons, it is deliberately not erased each time. This allows you to use MyChart as a simple template to develop your own custom graphics function.

The image is stored in Microsoft Enhanced Metafile Format in a temporary file whose name and location are generated automatically. The system does not delete the temporary file after use. For further details, See System.IO.Path.GetTempFileName.

The default program used to display the EMF file is SharpView.exe. You can opt to use a different EMF viewer by setting the Charts\ViewCMD registry key to name another program, such as Windows Picture and Fax Viewer.

An attempt to plot the contents of a variables with an unsupported data structure (see above) is handled entirely by error trapping and will result in an error message box and perhaps messages in the Status window.