I would recommend learning to use Plots instead!

On Tue, May 17, 2016 at 9:11 AM, <[email protected]> wrote:

> That looks like it might be exactly what I'm hoping to do. Coming from a
> gnuplot background, I'm having a lot of trouble with the Gadlfy syntax,
> though. I can't seem to find any comprehensive documentation that lists all
> of the commands/options, and trying to understand it inductively from the
> minimal examples on the Gadfly site is frustrating. So far I haven't been
> able to make the contour plot that I'm hoping to make. Is there a resource
> you would recommend for learning Gadfly?
>
> On Monday, May 16, 2016 at 11:56:14 AM UTC-4, Tom Breloff wrote:
>>
>> If your data is gridded (but just in vector form), then likely you could
>> just "zmat = reshape(z, numrows, numcols)" and then "contour(zmat)".
>>
>> On Mon, May 16, 2016 at 11:49 AM, <[email protected]> wrote:
>>
>>> Yes, my data is gridded. And no, I don't plan to sample these density
>>> values later. I just want to plot it and see what it looks like :) I'm not
>>> sure how to reshape the data into a 2D array though, or how to make a
>>> contour plot from a dataset rather than from a function. Is there anything
>>> on this in the documentation?
>>>
>>> Thanks for your help,
>>>
>>> Amelia
>>>
>>>
>>> On Friday, May 13, 2016 at 8:30:36 PM UTC-4, Scott T wrote:
>>>>
>>>> Two key questions - is your data gridded? And do you plan to sample
>>>> from these density values later, or are you just wanting to plot it and see
>>>> what it looks like?
>>>>
>>>> If your data is gridded (your ~10000 lines cover every combination of x
>>>> and y values in the range that you are interested in), then you can use the
>>>> contour command in Gadfly, which is the volcano plot you described. You'll
>>>> first need to reshape the data so it's a 2D array: think of it as
>>>> displaying a 2D image, where the number at each point is the density.
>>>> However, for displaying this kind of data, I prefer heatmaps, and I don't
>>>> know if Gadfly supports those - you may have to look into the histogram2d
>>>> command.
>>>>
>>>> If it is not gridded (the x and y points don't have any particular
>>>> structure to them), it's still possible, but you have to choose a way to
>>>> decide how you want to turn it from unstructured data into a 2D image. The
>>>> histogram2d approach that Tom showed above is one option, where you treat
>>>> each density measurement as a weighted measurement in a histogram. But if
>>>> your data represents single measurements of a function that has meaningful
>>>> values away from those measured points, you probably want to interpolate
>>>> between those points. For this you can use a package like Dierckx, which
>>>> does interpolations on unstructured data. I also have some simple code that
>>>> does barycentric triangular interpolation between unstructured points, in
>>>> case you wanted to have a look at that.
>>>>
>>>> This may be overkill, however, if you just want to look at the data and
>>>> don't plan to interpolate or draw from those density values later. If
>>>> that's the case, the trisurface plot above might be just what you need for
>>>> showing you the shape of your density data.
>>>>
>>>> Whatever you choose, I can recommend Tom's Plots package as a nice
>>>> interface to the other plotting packages in Julia - it makes it easy to
>>>> switch between different plotting options like Gadfly and PyPlot depending
>>>> on what features they offer.
>>>>
>>>> Cheers,
>>>> Scott
>>>>
>>>> On Friday, 13 May 2016 15:34:19 UTC+1, [email protected] wrote:
>>>>>
>>>>> Dear Julia users,
>>>>>
>>>>> I have a rookie question about plotting in Gadfly. I have some density
>>>>> data in a plain-text file in the form  of x y d, where d is the density at
>>>>> the point (x,y). I have about 10,000 lines of this data. I'm currently
>>>>> plotting old-school using gnuplot and since I don't like the looks of what
>>>>> I've been able to make, I'm hoping to be able to do something more elegant
>>>>> like Gadfly. I'm a relatively new Julia user as well. I like the "volcano"
>>>>> contour plot from the Gadfly documentation ( second plot from the top at
>>>>> http://dcjones.github.io/Gadfly.jl/geom_contour.html). I'm just not
>>>>> sure how to go about it.
>>>>>
>>>>> Has anyone done something like this before? I think it could be a
>>>>> really beautiful way to represent my data if I can get it to work. Any
>>>>> hints or suggestions would be greatly appreciated!
>>>>>
>>>>> Cheers,
>>>>>
>>>>> Amelia
>>>>>
>>>>
>>

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