Re: Plot a map of Europe

[Nicholas Jankowski]

On Tue, Nov 10, 2015 at 11:33 AM, Jorgen Sandberg <address@hidden> wrote:
>
> -----Original Message-----
> From: Francesco Potortì [mailto:address@hidden
> Sent: 10 November 2015 17:21
> To: Jorgen Sandberg <address@hidden>
> Cc: address@hidden
> Subject: Re: Plot a map of Europe
>
>>I have searched the internet, but not found a real "how to" instruction
>>on how to plot a map of for example Europe and add a contour on top. I
>>need to know the packages to install and where I can find map data in a
>>format accepted by OCTAVE. I really needs an idiots guide to plotting
>>maps in OCTAVE.
>
> Generally speaking, you can draw a plot on top of any background image.
> The general way to do so is something like
>
>     map = imread(mapfile);
>     image(map);
>     axis('image', 'off', 'nolabel');
>     hold on
>     plot(x, y);
>
> x and y should use the same measure of unit as the map, that is, pixels.
>
>
>
> Dear Mr Potorti,
>
> Thank you for the mail.
>
> I am trying to make M_Map work with Octave, but I am facing some 
> incompatibilities like "verLessThan" can't be found.
>
> Do you know of a way to plot a map of Europe that works with Octave?
>
> Regards,
> Jorgen Sandberg

Please respond at the end of the message as its the convention of this
mailing list and it makes it easier for others to follow the thread.

Had to google M_Map to realize what you were referring to. Apparently
it's an unofficial Matlab package developed by a University. A version
does appear to be hosted on both Matlab Central and the university
website.
http://www.eos.ubc.ca/~rich/map.html

My guess is that unless someone else here on the mailing list is
familiar with that particular package, you may have to dive into the
code yourself to find out what it relies on in Matlab that is not yet
fully compatible with Octave.  For example:

>> verLessThan
warning: the 'verLessThan' function is not yet implemented in Octave

Please read `http://www.octave.org/missing.html' to learn how you can
contribute missing functionality.

error: 'verLessThan' undefined near line 1 column 1


You are welcome to contribute an implementation of the verLessThan
function that is Matlab compatible while respecting their copyrighted
code. Of course, it is entirely possible that you will come across
another function with the same issue.

Alternatively, you could ask whether the University group has any
Octave users who would be willing to port the package.


Specific to your actual question:  you haven't really specified what
it is you mean by 'plot a map of Europe'.  Francesco showed you how to
add an image to your plot, and plot data on top of it, but it seems
that isn't what you meant.  It may be that some cases of what you like
to do are possible, but you'd have to write the code yourself. Someone
might be able to help you if you provide more detail.

What sort of data are you starting with? what does it look like, where
does it come from?  what output would you like to see with that data?

Nick J.