2022-06-21 14:26:36 +0200 received badge ● Notable Question (source) 2022-05-15 14:29:50 +0200 received badge ● Famous Question (source) 2022-01-30 19:49:29 +0200 received badge ● Popular Question (source) 2021-09-19 02:34:03 +0200 received badge ● Famous Question (source) 2020-12-09 13:12:25 +0200 received badge ● Notable Question (source) 2020-11-11 04:41:11 +0200 received badge ● Popular Question (source) 2020-10-17 21:09:04 +0200 received badge ● Popular Question (source) 2020-10-07 10:01:29 +0200 received badge ● Famous Question (source) 2020-07-17 21:06:24 +0200 received badge ● Famous Question (source) 2020-06-08 20:53:12 +0200 received badge ● Popular Question (source) 2019-12-14 14:14:37 +0200 received badge ● Notable Question (source) 2019-10-22 08:44:44 +0200 received badge ● Popular Question (source) 2019-09-09 10:25:19 +0200 received badge ● Popular Question (source) 2019-09-09 10:25:19 +0200 received badge ● Notable Question (source) 2019-08-26 10:19:10 +0200 received badge ● Famous Question (source) 2019-07-14 16:33:27 +0200 received badge ● Famous Question (source) 2018-07-04 16:24:59 +0200 received badge ● Popular Question (source) 2018-04-21 15:22:46 +0200 received badge ● Notable Question (source) 2017-09-12 23:37:53 +0200 received badge ● Famous Question (source) 2017-08-22 23:05:52 +0200 received badge ● Critic (source) 2017-08-17 00:18:50 +0200 asked a question Why does $\frac{2}{3} t - \frac{2}{3} y$ factors only when the variables are polynomial ring over the rational numbers? The expression $\frac{2}{3} t - \frac{2}{3} y$ can be factored as $\left(\frac{2}{3}\right) \cdot (y - t)$. If I try to use sage in this way to do the factorization: var('y t') E = -2/3*y + 2/3 * t E.factor()  The result is still E. On the other hand, if do it like this: R. = PolynomialRing(QQ) E = -2/3*t +2/3*y E.factor()  The result is as expected. Why does the call to factor() works as expected when the variable $y$ and $t$ are defined to be a polynomial ring in QQ and not work then they are symbolic expressions. 2017-08-17 00:09:24 +0200 commented answer How to get sage to keep the same form as an expression from sympy? If I type (y1-t1).mul(2/3, hold=true) it means that I already know the factorized form of the expression I want to factor. What if I don't know what the factorized form of the expression that I want to factor will look like? 2017-08-09 01:31:19 +0200 asked a question How to get sage to keep the same form as an expression from sympy? I have this expression: $$-\frac{2}{3} t_{1} + \frac{2}{3} y_{1}$$ and would like to rewrite it as follows: $$\frac{2}{3} (-t_1 + y_1)$$ Using sympy, I can get something close: import sympy as sp var('y1 t1') expr1 = -2/3*t1 + 2/3*y1 sp.factor(sp.sympify(expr1))  This gives: πΈ*(β―ππ·+π’π·)/πΉ  But when I convert it back to Sage: sp.factor(sp.sympify(expr1))._sage_()  The result reverts to expr1. How can I get the call to _sage_() not do any rewrites on the sympy expression? 2017-08-06 02:14:37 +0200 commented question How to assume the sum of some variables is equal to a constant? Thanks for the suggestion. Do you have any idea why assume() didn't work? 2017-08-06 02:13:58 +0200 commented answer How to assume the sum of some variables is equal to a constant? Any idea why assume() didn't work? 2017-08-05 08:08:05 +0200 asked a question How to assume the sum of some variables is equal to a constant? Suppose I have this expression: $$\frac{a {\left(t_{1} + t_{2} + t_{3} - 1\right)}}{b}$$ This can be simplified to 0 if we assume $t_1 + t_2 + t_3 = 1$. How can I accomplish this in Sage? I've tried: var('t1', 't2', 't3', 'a', 'b') expr1 = ((t1 + t2 + t3 - 1)*a)/b expr1.full_simplify() assume(t1 + t2 + t3 == 1) expr1.full_simplify()  I expected the second call tofull_simplify() to return 0 but it returned the same result as the first call, which is $$\frac{a t_{1} + a t_{2} + a t_{3} - a}{b}$$ 2017-08-04 01:09:07 +0200 asked a question How to reorder terms in an expression to follow a specific order? Suppose I have the following code: ti = var('ti', latex_name = 't_i') yi = var('yi', latex_name = 'y_i') expr1 = yi -ti  expr1 will display as $$-{t_i} + {y_i}$$ Is there a way I can rewrite expr1 so that it will display as: $${y_i} -{t_i}$$ ? I've tried using hold=True like so: expr1 = yi.add(-ti, hold = True)  but that did not work. 2017-08-01 18:15:57 +0200 received badge ● Good Question (source) 2017-07-31 15:40:18 +0200 received badge ● Nice Question (source) 2017-07-31 03:30:11 +0200 received badge ● Organizer (source) 2017-07-31 03:29:25 +0200 asked a question How to get Sage 8.0 to plot matplotlib plots inline and typeset expressions on a Jupyter notebook? If I start Sage 8.0 notebook using the jupyter notebook (sage -n jupyter), and the following code: from numpy import arange, sin, pi import matplotlib.pyplot as plt X = arange(0.0, 2*pi, 0.01) plt.plot(X, sin(X)) plt.show() x + 1  The plot displays inline but the expression $x+1$ is not typeset. If I run the following code: %display typeset from numpy import arange, sin, pi import matplotlib.pyplot as plt X = arange(0.0, 2*pi, 0.01) plt.plot(X, sin(X)) plt.show() x + 1  Then, the plot does not display inline. It shows: π΅πππππ(πΊπΉπΈπ‘πΈπΎπΎ)  However, the expression $x+1$ is in typeset. How can I have both the matplotlib plots display inline and expressions typeset? 2017-06-24 11:27:53 +0200 asked a question Can sage do symbolic optimization? I know sage has many functions to do numerical optimization. Now, I am wondering if sage can do symbolic optimization as well. For example, if I wanted to maximize a function using numerical methods, I could do this: f(x,y) = -(x * log(x) + y * log(y)) minimize(-f,[0.1, 0.1])  Which gives the answer: (0.367880005621,0.367880005621)  Is there a function that can give the solution as $(\frac{1}{e}, \frac{1}{e})$ or do I have to compute the stationary points and perform the necessary substitutions myself? 2017-06-08 03:08:39 +0200 commented answer Can I display a table of contents (TOC) in sage worksheet? Is there an equivalent add-on for Chrome? 2017-04-24 16:07:49 +0200 received badge ● Notable Question (source) 2016-10-24 14:20:55 +0200 marked best answer Can sage find the equilibrium solution to a first order differential equation? I was reading this to get up to speed on how to use sage to solve differential equations. I notice it made no mention of finding equilibrium solution. Does this mean that sage has no function that can be used to find the equilibrium solution for a given ordinary differential equation? 2016-09-10 00:45:08 +0200 received badge ● Popular Question (source) 2016-08-13 20:45:33 +0200 received badge ● Popular Question (source)