GNU Octave Manual Version 3 by John W. Eaton, David Bateman, Søren Hauberg Paperback (6"x9"), 568 pages ISBN 095461206X RRP £24.95 ($39.95) |
15.1.7 Test Plotting Functions
The functions sombrero
and peaks
provide a way to check
that plotting is working. Typing either sombrero
or peaks
at the Octave prompt should display a three dimensional plot.
- Function File: sombrero (n)
- Produce the familiar three-dimensional sombrero plot using n
grid lines. If n is omitted, a value of 41 is assumed.
The function plotted is
z = sin (sqrt (x^2 + y^2)) / (sqrt (x^2 + y^2))
See also surf, meshgrid, mesh
- Function File: peaks ()
- Function File: peaks (n)
- Function File: peaks (x, y)
- Function File: z = peaks (...)
- Function File: [x, y, z] = peaks (...)
- Generate a function with lots of local maxima and minima. The function
has the form
f(x,y) = 3*(1-x)^2*exp(-x^2 - (y+1)^2) ... - 10*(x/5 - x^3 - y^5)*exp(-x^2-y^2) ... - 1/3*exp(-(x+1)^2 - y^2)
Called without a return argument,
peaks
plots the surface of the above function usingmesh
. If n is a scalar, thepeaks
returns the values of the above function on a n-by-n mesh over the range[-3,3]
. The default value for n is 49.If n is a vector, then it represents the x and y values of the grid on which to calculate the above function. The x and y values can be specified separately.
See also surf, mesh, meshgrid
ISBN 095461206X | GNU Octave Manual Version 3 | See the print edition |