NCL > Application examples > Basic examples

ContourPlot example 12

Drawing filled contours over a map of Africa

This example demonstrates how to use HLUs and NCL to create a masked, filled contour plot over a map of Africa. The names of the example codes that create this plot are cn12c.c, cn12f.f, and cn12n.ncl.

Discussion

Some of the resources are controlled through a resource file called cn12.res.

A detailed discussion about how to create the plot appears in the comments of the source code for the example.

Creating the plot using HLU C library calls

The HLU C program that generates this plot is called cn12c.c.

Creating the plot using HLU FORTRAN library calls

The HLU FORTRAN program that generates this plot is called cn12f.f.

Creating the plot using NCL

The NCL script that generates this plot is called cn12n.ncl.

The data

The data for this example are generated using the GENDAT subroutine. However, the NCL script reads data from an ASCII data file called cn12n.asc.

How to run this example

The examples are installed in the following locations:

  • $NCARG_ROOT/lib/ncarg/hluex/contourplot/cn12c.c
  • $NCARG_ROOT/lib/ncarg/hluex/contourplot/cn12f.f
  • $NCARG_ROOT/lib/ncarg/nclex/contourplot/cn12n.ncl
The resource file for this example is located in:

  • $NCARG_ROOT/lib/ncarg/resfiles/contourplot/cn12.res
The data for the FORTRAN version of this example is located in:

  • $NCARG_ROOT/lib/ncarg/data/asc/cn12n.asc
You can copy this example and run it by typing "ng4ex cn12c", "ng4ex cn12f", or "ng4ex cn12n". A copy of the source file and resource file will be placed in your current working directory. The source code will be compiled and automatically run for you.