Re: [sage-support] Re: integral() error
Hello Justin thanks for this...I'm more familiar with the R help list, where there's a very heavy emphasis on not wasting bandwidth, and replies not much less terse than 'rtfm' are very common. So, I'm finding the more tolerant atmosphere in sage to take some getting used to! best wishes Robin On Mon, Sep 5, 2011 at 4:30 PM, Justin C. Walker jus...@mac.com wrote: Hi, Robin, On Sep 4, 2011, at 16:10 , robin hankin wrote: Hello Justin thanks for this. (I'm a linux user but currently getting to know macosx). If you use linux, you aren't that far from (command-line) Mac OS X. It's basically a BSD unix at that level. $SAGE_ROOT was null, but I can run it from the commandline by changing to Applications/Sage-4.7.1-OSX-64bit-10.6.app/Contents/Resources/sage/ and running ./sage. As I said, you had to replace $SAGE_ROOT with a real path. But you've gotten past this. And the integral() command seems to work but I have other problems: wt118:/Applications/Sage-4.7.1-OSX-64bit-10.6.app/Contents/Resources/sage% ./sage -- | Sage Version 4.7.1, Release Date: 2011-08-11 | | Type notebook() for the GUI, and license() for information. | -- sage: 2+2 4 sage: integral(x^2,x) 1/3*x^3 sage: quit() 'quit' is a command, not a procedure call; in both Python and iPython, you call quit(), but apparently, in Sage, not so much :-}. Note that Sage is essentially Python, with a modified iPython front end, and a bit of syntactic sugaring with a preparser. We throw a few things like this in just to keep the hapless user on his toes. Or hers. I'm beginning to think I should reinstall from scratch (or indeed compile my own). No need. The precompiled version should work just fine. You only have to survive the learning curve :-} Keep asking questions and reading documentation. Apropos of documentation, there is a lot available http://www.sagemath.org/help.html#SageStandardDoc but what's there can always use improvement. Feel free to browse and either ask questions or submit bug reports (cf. http://www.sagemath.org/development.html). Also, there is some built-in documentation in Sage. To get an idea, type (at the prompt) the beginning of a procedure name (e.g., there is one that creates a number field): sage: Number[TAB] should produce a list of four known Sage identifiers. Typing sage: NumberField? will get you the sourcecode documentation for this procedure. Using ?? instead of ? will get you the documentation plus source code, so you can see the implementation details. That may help get you started. We're here to help. Sometimes, we succeed. Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Absorption of Federal Funds If you're not confused, You're not paying attention -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -- Robin Hankin Uncertainty Analyst hankin.ro...@gmail.com -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] Warnings and lines
Two questions, how to turn off divide by 0 warnings and how to draw a line over a plot. I was trying to draw a horizontal line at the equilibrium solution at y = -3. set_verbose(-1) #Turn off warning s1 = -3 p1 = plot_slope_field(((y+3)/(1-y)), (x,-6,6), (y,-6,6)).show(aspect_ratio=1) p2 = plot(s1) show (p1+s1) Thanks, -d -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: Warnings and lines
set_verbose(-1) #Turn off warning I think there is a way to turn off those warnings, but I think one has to do it from within Numpy. s1 = -3 p1 = plot_slope_field(((y+3)/(1-y)), (x,-6,6), (y,-6,6)).show(aspect_ratio=1) You should assign the plot itself to p1. Currently you've assigned the show - probably None is returned? to p1. p2 = plot(s1) show (p1+s1) And now you added -3 to the show. Try sage: p1 = p1 = plot_slope_field(((y+3)/(1-y)), (x,-6,6), (y,-6,6)) sage: p2 = plot(s1,-6,6) sage: show(p1+p2,aspect_ratio=1) Good luck! Hopefully someone else who doesn't have to run to work will remember how to shut off the warnings. In any case, there is a ticket open related to this, upstream has been informed (because they are not really valid, it's related to our slope field lines having arrowheads of zero size). - kcrisman -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] writing solution in sage to OpenCV cvSolve
hi, new to this list, but using sage for some time. I have a function E(Xc,Yc,Zc) which calculates the squared distance of camera center 3d coordinates (as per paint-brush laser scanner by Zagorchev Goshtasby). I have the partial derivatives of E Xy Yc and Zc which are set to zero. My problem is that the function is very long, using real measured 3d coordinates in the double frame. My code is in c++ using OpenCV. I'd like to use cvSolve to calculate the 3d camera coordinates, but writing the A matrix and b vector by hand is very tedious and prone to typos, so using sage to set up the matrix would be ideal. I've googled and searched the sage documentation, but not finding an easy way to do this. Even getting the variables to left- hand side and the constants to right-hand side would help a lot. I know nearly nothing about python, but I think it should be able to write a function which outputs directly code for OpenCV. Are there any sage functions to simplify the process? thanks -matti -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] w/ sliders in interact functions, how apply format strings to the numbers? (Want to truncate decimals!)
This slider will display the corresponding numbers as the slider is moved @interact def _(a=slider(1, 2, 0.2)): print test The problem is the numbers have too many digits for my taste... e.g. 1.00, 1.20, 1.40, etc. How truncate or round or format? Thanks! Chris -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] w/ sliders in interact functions, how apply format strings to the numbers? (Want to truncate decimals!)
On Tue, Sep 6, 2011 at 10:15 PM, Chris Seberino cseber...@gmail.com wrote: This slider will display the corresponding numbers as the slider is moved @interact def _(a=slider(1, 2, 0.2)): print test The problem is the numbers have too many digits for my taste... e.g. 1.00, 1.20, 1.40, etc. How truncate or round or format? Here is one way: @interact def _(a=slider(1, 2, RealField(5)(.2))): print test, a, RR(a), RR(str(a)) Note -- here a will be a 5-bit real number, so you may want to convert it to a full 53-bit number before using it. One way to do that which will preserve the *print output* is RR(str(a)). That will probably be less confusing to users than RR(a). William Thanks! Chris -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -- William Stein Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] How make/hack 1D real number line plots like we learned in elementary algebra?
Sage can do great 2D and 3D plots. What about baby 1D plots that would be really nice for the kids? If I select a number using an interact widget, it would be nice to see a plot of a 1D real number line with the selected point appear as a big colored dot. Plots of solutions to inequalities like x 1 would be icing on the cake and involve the same big colored dot with a ray drawn to one side. Any examples somewhere? Chris -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
