gnuplot-info

[Gnuplot-info] pm3d of the matrix with variable row length.

[<v_...@uk...>]

  Hello!
  I have the following problem: 

There are some data in a matrix form like this:

2.5 2.5 2.4 2.4 2.4 2.4 2.4 2.4
2.4 2.4 2.3 2.3 2.3 2.3 2.3
2.3 2.3 2.1 2.1 2.1 2.1 2.2
2.2 2.1 1.9 1.9 1.9 1.9 2.1
2.1 2.1 1.7 1.7 1.7 1.7 2.0 2.3
2.1 2.0 1.6 1.6 1.6 1.6 1.9
2.0 1.9 1.5 1.5 1.5 1.5 1.8
1.9 1.8 1.4 1.4 1.4 1.5 1.7 2.2
1.8 1.7 1.4 1.4 1.4 1.5 1.7

As one can see, there are strings with different number of columns. The
Gnuplot manual says that "pm3d ... allows plotting gridded as well as
non-gridded data without preprocessing, even when the data scans do not
have the same number of points." So I've tried to do it in the several
ways, but failed.
  The last command I tried to use looks like this:

gnuplot -e 'set terminal png; set pm3d map flush begin; set
palette color negative; splot "mydata.txt" matrix with pm3d'

I believe it is the part "flush begin" that must help plotting a matrix
with different number of columns in the rows, isn't it?

If someone has successfully plotted a matrix similar to mine, please
give your example.

P.S. By the way, there is an example of what I want to get here:
http://gnuplot.sourceforge.net/demo/pm3d.html 
It is called "Datafile with different nb of points in scans; pm3d flush
begin".

  Thank you.
    Vladimir

----- 
 <v_...@uk...>

Re: [Gnuplot-info] pm3d of the matrix with variable row length.

[<v_...@uk...>]

On Tue, 05 Jul 2011 22:30:52 +0200
Hans-Bernhard Bröker <HBB...@t-...> wrote:

> On 05.07.2011 22:24, v_...@uk... wrote:
> 
> >    I thought so too, but it looks like I do not have them. At
> > least, the command
> >      find /usr -name 'triangle.dat' gives nothing.
> 
> That's by no means conclusive proof.  If you built your own gnuplot,
> the demos could be anyway (in the source, or installed in whatever 
> location).  Or your distributor might have decided to put them
> somewhere unexpected (possibly even in a separate package you didn't
> install).
> 
  Well, I implicitly meant that I installed gnuplot in a standard way
using the package manager. And in such cases [almost] everything goes
under the '/usr' directory. Any additional data goes into the
'/usr/share' usually.
  But anyway thank you for the tip about the package manager options.
It did turn out that the Gnuplot demos installation depends on the
configured package manager options. And I had the necessary option
turned off.
  It also turned out that the file 'triangle.dat' isn't in a matrix
form. It explains why it works. But still, isn't it possible to work
with a matrix with a variable row lengths?

> >    By the way, if you have this file on your machine, could you
> > please send it to me?
> 
> I'd rather resolve how it can happen that you don't have it.
> 


----- 
 <v_...@uk...>

Re: [Gnuplot-info] pm3d of the matrix with variable row length.

[Hans-Bernhard B. <HBB...@t-...>]

On 05.07.2011 23:26, v_...@uk... wrote:

>    It also turned out that the file 'triangle.dat' isn't in a matrix
> form. It explains why it works. But still, isn't it possible to work
> with a matrix with a variable row lengths?

Apparently not.  gnuplot is quite straight forward about it in its error 
message, too:

          Matrix does not represent a grid

And if you think about it, I hope you'll agree that something with 
variable row lengths, pretty much by definition, is _not_ a matrix.

Re: [Gnuplot-info] pm3d of the matrix with variable row length.

[<v_...@uk...>]

On Tue, 05 Jul 2011 23:45:39 +0200
Hans-Bernhard Bröker <HBB...@t-...> wrote:

> 
>           Matrix does not represent a grid
> 
> And if you think about it, I hope you'll agree that something with 
> variable row lengths, pretty much by definition, is _not_ a matrix.
> 
  You are right of course. But I still need to plot those data and I'd
be happy to get any suggestions or advices on how to do that in my
particular case (with the data I posted in the very beginning of this
thread). Can I use that file without reformatting it into a 3-column
(X, Y, Z) format?

  Thanks
    Vladimir

----- 
 <v_...@uk...>