[9fans] grap problem

[Rudolf Sykora]

Hello everybody,

I've been surprised by the behaviour of grap acting on e.g. this source

.G1
coord  y 1,3
2
3
4
.G2

I expected the point 4 is not to be drawn.
But I see the point drawn outside the frame... which is not what I want... (I want the data outside the limits to be ignored...)
What am I doing wrong?

Thanks for help!
Ruda

[Lyndon Nerenberg VE6BBM/VE7TFX]

> (I want the data outside the limits to be ignored...)
> What am I doing wrong?

Not filtering your input data? grap's only intent is to typeset the
data you feed it. 'coord' sets the ranges for the graph scales. It
doesn't filter the data -- that's your job. (As a typesetting design
device I might want to plot data points outside the graph axis limits
-- grap rightly doesn't prevent me from doing that.)

[Rudolf Sykora]

2009/12/20 Lyndon Nerenberg (VE6BBM/VE7TFX) <lyn...@orthanc.ca>

Thanks.
It's always a question whether the plotting program (here grap) should only typeset given data or be able to do more. If it only can typeset, you have to prepare data in advance, which means there is an intermediate step (e.g. when you want to plot all data and then some detail of the same data, and do this over many times, producing the 'detail' data file every time is kind of awkward and error prone; the same holds if you need do some simple operation with the data). Fortunately, grap can do some simple things. Even my desire can be fulfilled with the 'if' statement, which finally was the way I had proceeded.

Btw., my trying to use the 'coord' command originated from reading this

http://www.lunabase.org/~faber/Vault/software/grap/example/

(search for 'detail' on this page and the graph below it), which now seems to be not so simple...

Thanks
Ruda