From octave-graphics-request at bevo dot che dot wisc dot edu Sun Oct 27 19:10:54 2002
Subject: Re: Trouble with plplot_octave
From: Joao Cardoso <jcard at fe dot up dot pt>
To: =?iso-8859-1?q?J=E9r=F4me=20LEFEVRE?= <jlefevre at mls dot nc>,    <octave-graphics@bevo.che.wisc.edu>
Date: Mon, 28 Oct 2002 02:14:05 +0100

On Saturday 26 October 2002 10:22, Jérôme LEFEVRE wrote:
> Hi,
>
> Recently, I have installed PLPLOT 5.1. with Octave. This plot tool is
> promising.
>
> However, I would like to know more about Octave/plplot setting and column
> format, cause i meet trouble.
>
> First, with plplot_octave_demo, demo x01c and x03c abort with dimension
> mismatch in dimension x.
>
> In a last mail (11 Mar 2002), Douglas Eck wrote to John W. Eaton :
>
>     The plplot demos do not run with my configuration with
> prefer_column_vectors = 0 (debian sid running octave-plplot and latest 2.1
> octave packages) The problem is somewhere in plplot_octave.oct and so I'm
> not getting a trace. I'm sure it's an easy fix but I don't have time today
> to track it down. Basically x and y need to be column vectors.
>
> With, prefer_column_vectors set to 1, I can note that plplot_octave_demo
> run.
>
> But, i meet trouble with my own data, like : (x and y, geographical
> coordinate) x = 400 000        y= 4 000 000
>       400 100            4 000 100
>       400 200            4 000 200
>      ...                   ....
> N=length(x)       ( with length(x)= length (y)= 2000)
>
> If i call plpoin (N,x, y) : Octave say "dimension mismatch in argument x
> called from 'plpoin' " If i call plline (N,x,y) : Octave say "dimension
> mismatch in argument y called from 'plline' "

with plplot_octave you don't need to specify the array dimensions. If you:

octave:1> plplot_stub 
octave:2> help plpoin 

plpoin is a user-defined function

plpoin(x, y, code)
^^^^^^^^^^^^^^^^
  Original PLplot call documentation:
  ^^^^^^^

plpoin: Plots a character at the specified points 

Marks a set of n points in  x and y using the symbol defined by code. If code 
is
 between 32 and 127, the symbol is simply the corresponding printable ASCII 
char
acter  in the default font. 

plpoin(n, x, y, code)
^^^^^^^^^^^^^^^^^
...

And you need to pass column vectors, plplot_octave ignores your preferences.

Joao

>
> My octave setting are :
>
>   PS1 = ">> "
>   PS2 = ""
>   beep_on_error = 1.0
>   default_eval_print_flag = 0.0
>   default_save_format = "mat4-binary"
>   define_all_return_values = 1.0
>   do_fortran_indexing = 1.0
>   empty_list_elements_ok = 1.0
>   fixed_point_format = 1.0
>   gset_mouse = 1.0
>   gnuplot_has_multiplot = 1
>   implicit_num_to_str_ok = 1.0
>   implicit_str_to_num_ok = 1.0
>   ok_to_lose_imaginary_part = 1.0
>   page_screen_output = 0.0
>   prefer_column_vectors = 1
>   prefer_zero_one_indexing = 1.0
>   print_empty_dimensions = 0.0
>   treat_neg_dim_as_zero = 1.0
>   warn_function_name_clash = 0.0
>   whitespace_in_literal_matrix = "traditional"
>
> Many thanks for your hint.
>
> Best regards.
>
> Jerome Lefevre.