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Using Seaborn Graphing in Sagemath Seaborn is a matplotlib frontend that makes beautiful graphics by default, without a

When I ran solve, it wouldn't halt. That's why I was trying mpmath.

At least that's a mathematical one. Can't believe I missed that typo!

That's good to know, but I wonder why I couldn't get that result after trying the same things you did. I'm running Sage

mpmath not working with sage equations I'm trying to get a numerical solution to a problem similar to the one discussed

I'm trying to use implicit_plot to graph nullclines for a competition model, but only some parts of the nullclines are plotted. I have:

var("N,P")
Nprime(N,P) = N*(3-N-2*P)
implicit_plot(Nprime, (N,0,3), (P,0,3))

Clearly, this function is 0 at all points where N=0, but the graph only shows them up to P=3/2. Is there anything I can do to avoid this or is it a bug in implicit_plot?

Thanks. Is there a way to incorporate something like a square wave into an ODE in Sage without using Python functions?

I'm trying to numerically solve a two-variable system of differential equations with a periodic external driver (square wave). Right now, the code I have is:

from scipy.signal import square
def sqstim(t, amp=1): 
    return (amp/2)*float(square(t))+amp/2

var("V,w")
trange=srange(0,100,0.1)

def eqns(t):
    return [1/100*(-w+(V^3-V)+sqstim(t)), V-0.2*w]

sol=desolve_odeint(eqns, times=trange, ics=[0.1,0.1], dvars=[V,w])

This gives "TypeError: 'function' object is not iterable". What should I do instead?

I would use:

sol=solve(x^2-4==0,x)
[eq.rhs() for eq in sol]

The .rhs() method extracts the right-hand side of an equation.

Is it whole cells that disappear or pieces of code within cells?

I'm trying to run the sample clickable interact given by William Stein at http://permalink.gmane.org/gmane.comp..., but nothing happens when I click on the image. The code is

@interact
def f0(fun=x*sin(x^2), mousemove='', click='(0,0)'):
    click = sage_eval(click)
    g = plot(fun, (x,0,5), zorder=0) + point(click, color='red', pointsize=100, zorder=10)
    ymax = g.ymax(); ymin = g.ymin()
    m = fun.derivative(x)(x=click[0])
    b =  fun(x=click[0]) - m*click[0]
    g += plot(m*x + b, (click[0]-1,click[0]+1), color='red', zorder=10)
    def h(p):
        f0.mousemove = p
    def c(p):
        f0(click=p)
    show(g, events={'click':c, 'mousemove':h}, svg=True, gridlines='major', ymin=ymin, ymax=ymax)

Also, what is p in this code? Is there any documentation on clickable interacts in SMC?

I'm trying to make a simple interactive for my students to practice differentiating polynomials. For some reason, when an answer is entered, Sage tries to convert it (a polynomial) to an instance of sage.structure.parent.Parent and chokes. The same code run outside of an interactive works fine. Why is Sage trying to do this conversion and how do I get it to stop?

#Create polynomial generator
poly.<x>=PolynomialRing(QQ)

#Problems correct (in a row and total)
streak = 0
tot = 0
first = True

@interact
def polyDiff(ans=input_box(label="f'(x)=", type=sage.rings.polynomial.polynomial_rational_flint.Polynomial_rational_flint)):
    #Load persistent variables
    global streak
    global tot
    global first

    global poly

    #Set up and display problem on first run
    if (first == True):
         rand_poly=poly.random_element(2)
         first = False
    html("f(x)=")+html(rand_poly)

    #Define correct answer
    corr = diff(rand_poly, x)

    #Check student's answer
    if (ans is not None):
        if (corr == ans):
            print "Correct!"
            tot += 1
            streak += 1
            #Generate new problem
            rand_poly = poly.random_element(5)
        else:
            html("Try again")
            streak = 0
    else:
        print "Enter your answer"

I'm trying to plot a grid graph, specifying exactly where vertices should be plotted. (I want the plot to look like an actual grid and later overlay a graphics object on it.) The following code gives a KeyError:

G=graphs.GridGraph([8,12])
pos_list=[(i,j) for i in range(8) for j in range(12)]
pos_dict={}
for i in range(len(pos_list)):
    pos_dict[i]=pos_list[i]
G.show(pos=pos_dict)

How can I get my plot to look like a regular grid?

I'm writing an interactive and want the two pull-down menus and the update button to all appear in one row. @interact(layout={'top': [["ansA", "ansB"]]})works fine but doesn't show the update button. How do I include it in the layout?

I'm running Sage 5.8 on Ubuntu 12.10 and am trying to install some R packages within Sage. However, when I enter

%r
install.packages("deSolve")

I get a green line and nothing happens. I am not asked what repository I'd like to use; when I specified a repository, I still got a green line and nothing happened. If I leave out the package name, I get a pop-up asking what package I want to install but nothing after that. What should I do?

I'm running Sage 6.4.1 (on Ubuntu 14.04 and Firefox 34.0) and using the IPython notebook. It's a great interface, but interactives aren't working. For example, the following brings up a bunch of HTML rather than an actual interactive.

@interact
def test(a=(-3,3)):
    p=plot(a*sin(x), (x,-2*pi, 2*pi))
    show(p)

Do interactives work differently in the IPython notebook?