I find several links(e.g. this one) about the size or resolution of figures plot by matplotlib.
Like , we can use pl.show(), and zoom in or zoom out before we save the figure. We can see as many details as possible in this way.
However, after we specify a dpi value in pl.savefig and save the whole figure*(png format), the details like above are lost.
Even we use a svg format, the improvement is limited like
What is the best way then? After we save the figure, can we display it and adjust it like pl.show()?
However, after we specify a dpi value in pl.savefig and save the figure, the details are lost.
The details aren't lost if you save the figure as pdf or svg, they are vector formats. Just try opening one of them in e.g. Inkscape, and you can select or edit every individual line segment.
The difference between zooming in a Matplotlib window or a saved figure is that the line width isn't re-scaled when you zoom in e.g. the saved PDF (which of course is a good thing).
After we save the figure, can we display it and adjust it like pl.show()
If that's what you want, why not simply re-run your Python script?
Related
I'm asking my question here because I haven't find any information that could solve my problem. With FuncAnimation, I'm plotting the coordinates of a moving point on a world map. Every coordinates that I take from a CSV file come from a function where I implement myself the time spending. The data are then send to a csv file that I call in my FuncAnimation function.
This is how my CSV file look like:
enter image description here
All the plotting is working but I want to improve it. This is how my plot looks like at a period t:
I would like to know if someone knows a command that would permit me to plot my coordinates and the time (on the bottom left for example) like the time spending at the bottom left of the window on my computer, something like plt.time(position= 'bottom left', time_list).
The time value would be taken from my CSV, and open as a list (time_list) at the beginning of the code.
I tried to find the function on internet but didn't find anything except how to put the time as an axe which is not what I want.
I have an SVG file of a bar plot that I need to convert to a PDF. The bar plot was made in matplotlib, saved as a PDF and imported into Inkscape. I used Inkscape to add annotations to the figure and then export it back to a PDF to be used in a final document.
This is what the PDF file looks like going into Inkscape
After adding text elsewhere on the figure and saving as a PDF I get the same plot with these white lines:
These are not your typical PDF render artifacts, rather a closer inspection shows that they have a gradient to them.
I think this is somehow a product of the SVG file. I have used an online SVG-to-PDF converter and the lines are still present. Additionally, I use this method to make all my figure, Matplotlib to Inkscape to PDF and I have not had this issue with any other figures.
I've found that Inkscape does this when you import a bar graph which has a shading type that is not the same as any of the preset Inkscape patterns. I've seen this exact issue when I've imported graphs from R programing language and excel so I don't think it's specific to Matplotlib. I don't know the root cause, however, since I experience this problem a lot I'll share the workaround options I typically employ when I get this issue. One is not necessarily better than another and it depends on the situation which I use.
Option 1) Convert the PDF to a .png bitmap image in some other program, (Gimp, Photoshop, Powerpoint....) then embed the image in Inkscape. Make your changes then export from Inkscape as a PDF. This has the disadvantage that the graph will no longer be a vector map. Use option 2 or 3 to keep it a vector map.
Option 2) Import the pdf into Inkscape, ungroup the pdf object, delete the stripped filling in the bar graph, then recreate the filling using an Inkscape made fill. In the worst cases I've actually made custom bar graph patterns in Inkscape to exactly match the pattern that I had before. This process is a pain.
Option 3) Create shapes that cover over the artifacts, remove border lines from the shapes and use the eye dropper to make them exactly the same color as the good parts.
Like I said these are not an academic understanding of the problem to avoid the problem but I hope it can help you accomplish your task.
I am looking for a way to measure the coordinates of different rectangles on a PDF file?
Mainly I do have to perform some overprinting on an existing PDF and I need to know the x,y,w,h on where I am supposed to write the texts.
It seems that Preview.app on Mac has this ability but so far I wasn't able to find anything on Windows that does the same.
Please do not confuse this feature with the Measuring Tools from Adobe Reader which are used to measure distance in printed construction stuff, not the PDF page itself.
It seems that the default using of measure is point, so I need something that would allow to select a rectangle and that will tell me the coordinates.
Please do not suggest on exporting as a imagine and using something else to measure the pixels on the image.
Update: http://legacy.activepdf.com/support/knowledgebase/view.cfm?tk=rl&kb=11866 -- PDF Units, that's what I am looking for, something to measure the PDF coordinates in PDF units.
Disclaimer: I work for Atalasoft.
I know you said not to suggest this, but honestly, it's the easiest approach:
If you mean "sweep out a rectangle in the UI and report the coordinates", that's pretty straight forward, but it's going to be a build-your-own type of thing. What you will need are:
A PDF rasterizer (GhostScript, Acrobat, FoxIt, Atalasoft) to get you an image at a specific resolution.
A tool to display that image in a window and let you sweep out a rectangle (this is straight forward winforms type code for .NET, but we have a control that does this out of the box - combining 1 & 2 into one step).
A tool that can look at the structure of a PDF page and report back the crop box (if any) and the media box for each page (iText, DotPdf).
A tool/understanding of matrix transformations to build the matrix that goes from display space into PDF space (and/or vice versa, probably in iText, definitely in DotPdf)
The code flow becomes something like:
For each page:
Open document, pull out crop and media box, rasterize page, build transformation matrix.
Display image, build/hook into event for selection changing.
Push the image viewer rectangle coordinates through the transformation matrix.
Profit.
From a coding point of view (assuming 0 prior knowledge of this, but a decent understanding of linear algebra), from 3 days to a 2 weeks. If I were to write it, it would probably take on the order of a few hours, but I wrote most of our PDF tools and this is pretty easy.
If your goal is to intuit where rectangles are on the page and report back those coordinates, that's also doable, but it decidedly non-trivial in comparison. You need to write code that can rip through a PDF display list and interpret the contents correctly. That means being able to handle all the cumulative matrix transformations, the graphics state changes, the gstate object use, Form XObject placement, and so on. You need to answer the question "what is a rectangle?" because in PDF placement, it could be an re operator, a set of degenerate beziers, a set of lines, an image of a rectangle or (surprise!) a combination of all of the above. Honestly, intuiting anything about the content on a PDF page is a Herculean task.
What I am ultimately trying to do is to create a grid of images for print that are minor variations of the same thing (different text is all). Looking through online resources I was able to create a script that changes the text and exports all of the images necessary (several hundred). What I am trying to do now is to import all of these images into a new photoshop document and lay them all out in a grid and I can't seem to find any examples of this.
Can anyone point me in the right direction to place a file at a specific coordinate (I'm using CS5 and have the design suite so if there is a way in illustrator to do this quickly...)?
Also, I'm open to other ideas on how to do this (even other programs) easily. It's for labels so the positioning on the sheet has to be pretty precise...
The art layer object has a translate() method that takes delta x and y params. You'll need to open each image, copy it to the target document, get its current location (using artLayer.bounds) and do the math to find the deltas to position it where you want it. Your deltas can be in pixels so you'll get plenty of precision.
Check out your 'JavaScript Scripting Reference' pdf in your Adobe install directory for more details.
Ok I'm marking Anna's response as the answer because though I didn't fully test it, it seems like it should work and answers the original question with jsx. However I'm also leaving my final solution in case anyone else runs across this with the same issue and may prefer this method as well.
What I ended up doing instead is using InDesign. I figured out that it has a grid option that lets you import a number of files and place them all in an equal grid in a single command. This is almost exactly what I was looking for, except that it leaves a small border/margin in between the columns and grids and mine were designed to meet exactly.
I couldn't figure out how to make it not have the border (I have very little experience with InDesign, it may be possible). However I was able to select all my images and scale them uniformly to be the correct size, then I just selected each column and dragged it over to snap to the adjacent column and the same with rows...
I generate a figure in MATLAB with large amount of elements (100000+) and want to save it into a PDF file. With zbuffer or painters renderer I've got very large and slowly opened file (over 4 Mb) - all points are in vector format. Using OpenGL renderer rasterize the figure in PDF, ok for the plot, but not good for text labels. The file size is about 150 Kb.
Try this simplified code, for example:
x=linspace(1,10,100000);
y=sin(x)+randn(size(x));
plot(x,y,'.')
set(gcf,'Renderer','zbuffer')
print -dpdf -r300 testpdf_zb
set(gcf,'Renderer','painters')
print -dpdf -r300 testpdf_pa
set(gcf,'Renderer','opengl')
print -dpdf -r300 testpdf_op
The actual figure is much more complex with several axes and different types of plots.
Is there a way to rasterize the figure, but keep text labels as vectors?
Another problem with OpenGL is that is does not work in terminal mode (-nosplash -nodesktop -nodisplay) under Mac OSX. Looks like OpenGL is not supported. I have to use terminal mode for automation. The MATLAB version I run is 2007b. Mac OSX server 10.4.
This is a funny one. Your problem is not Matlab, it's Ghostscript (Matlab creates PDFs by calling Ghostscript, at least on Windows). When I run
x=linspace(1,10,100000);
y=sin(x)+randn(size(x));
plot(x,y,'.')
print -dpsc2 test.ps
I've got a 2Mb PS file (all vector, of course), which when compressed became a 164Kb ZIP. One would expect to get more-or-less the same result when converting PS to PDF, but ps2pdf test.ps produced your 4Mb file!
Since you are on a Mac, you probably have Distiller. I'd give it a try — generate PS files as above, and then run them through Distiller; you should get a 150K vector PDF.
If you insist on rasterizing, I can suggest printing the figure without any axes or labels to a tiff, opening the tiff, and recreating axes and labels on top of it.
If you don't want to go with a 2D histogram (i.e. an image where pixel brightness corresponds to density of points) as BlessedKey suggests, it looks like the only good way is to do the rasterizing yourself, as mentioned by AB.
getframe followed by frame2im seems to be the way to go for that. Unfortunately, getframe returns empty if you run with -nodisplay. Therefore, you'd have to save the figure as .fig, and on another computer run a script that
opens the figure, gets the content of the axes with getframe, displays the image from getframe and then saves to pdf.
As an alternative to simple plotting or a 2D histogram, you may want to look into scattercloud, which combines plotting the points with density information, by the way.
If at all possible you should try to subsample your problem before building the illustration. If you are plotting points on a curve then 10,000 is probably more than you need. A modern printer is only about 600 DPI afterall.
If the points are illustrating a cloud with some density properties, a better solution may be to build a two dimensional histogram first, and illustrate that with imshow or imagesc.
If multiple clouds are being illustrated with different colors you may be interested in building one such image for each cloud and the combining them with transparency.