home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Fatted Calf
/
The Fatted Calf.iso
/
Applications
/
Graphics
/
ContourPlot
/
README
Wrap
Text File
|
1994-05-17
|
5KB
|
104 lines
ContourPlot.app demonstrates the use of object class ContourView, but
at the same time it tries to be a usable application for generating
contour plots WITH COLOR FILLS from 2-dimensional grid data.
While I have seen many contour plot routines and programs that produce
contour lines in color, I could not find any that could FILL regions
inside contour paths. Hence, the ContourView class and this application.
It can only handle 2-D data on a regularly spaced Cartesian grid.
ContourPlot reads 2-D grid data files in a simple ASCII format which
may be generated easily by other programs. See the Info/Help Panel
and a sample data file for details of the file format.
* Press File -> Open Sample File on the menu for a demo plot.
* Press File -> View Sample File on the menu to look at the data
file that generates the demo plot.
Plots may be copied to the pasteboard as EPS (Encapsulated PostScript)
by clicking the plot area once and pressing Edit -> Copy on the menu.
Then, the plot may be pasted into documents that accept PostScript
data, such as NeXTMail Compose window (In NeXTMail mode), Edit document
(in RTF mode), ohter drawing/layout apps.
To save to an EPS file, first paste into a Yap (or my BBFig)
(/NextDeveloper/Apps/Yap.app) document, then save from Yap.
From ContourView README.
-------------------------------------------------------------------------------------
Distinguishing features of this ContourView class are:
[1] It does color fills within contours just like colored geological maps.
As far as I am aware, this is the only public domain source code that can
do this for PostScript, not as bitmaps. (Let me know if you know of
any other PD code that does color-filled contour plots.)
[2] It is a pretty self contained object in the form of a View subclass.
[3] PostScript may be copied onto pasteboard and pasted into other apps that
accept EPS data. Try pasting it into Yap document, NeXTmail compose
window, Edit RTFD document, etc.
There is really no documentation. Look at the class implementation file
ContourView.m and an example test application ContourPlotApp.m for usage
information. The app included here is just for testing ContourView
class. ContourView is meant to be included in your apps like any other
objects.
It is pretty easy to use. If instantiated within IB, all you need to do
to get a plot is to call the following two method to get a default
plot. If you understand the following method, you can use the
ContourView object easily.
- setCartesianGridData:(float *)f :(float)xmin :(float)xmax
:(float)ymin :(float)ymax
ofSize:(int)nx :(int)ny
withInterpolationTo:(int)n1x :(int)n1y;
f[nx*ny] is a 1-d array containing 2-d grid data such that f[iy*nx+ix]
contains the value at (ix, iy).
Typicall, just 3 messages below will produce a contour plot with color
fills.
[contourView setCartesianGridData: fdata :1.0 :5.0 :1.0 :5.0
ofSize: 20 :20
withInterpolationTo: 50 :50];
[contourView setFillEnable:YES];
[contourView display];
-------------------------------------------------------------------------------
TO USE:
ContourView class consists of the following modules/files. Other files are
the glue needed for the test application ContourPlot.app. When incorporating
ContourView into your app, you need to copy only the follwoing to your
project directory:
ContourView.h
ContourView.m (Class implementation)
computeContour.m (contour path computation engine)
contour.h
sortContour.c (sorting of contour path based on inclusion relation)
splin2.c (bicubic spiline)
splin2.h
-------------------------------------------------------------------------------
This can use a lot more optimizations which should speed up the drawing
significantly. Some of these are:
[1] All parameter changes currently trigger recomputation of all contour paths,
because almost everything is done in drawSelf:: method.
This should not be necessary for some. E.g., changing fill colors, line
width etc should not cause recomputation of contour paths.
[2] Use DoUserPath() etc to optimize drawing.
[3] Some methods are not yet implemented (It does what I wanted now).
-------------------------------------------------------------------------------
Send comments, bug reports, suggestions and improvements to below:
---
Izumi Ohzawa, Ph.D. [ $@Bg_78^=;(J ]
USMail: University of California, 360 Minor Hall, Berkeley, CA 94720
Telephone: (510) 642-6440 Fax: (510) 642-3323
Internet: izumi@pinoko.berkeley.edu (NeXT Mail OK)