I am using SymPy’s plotting module, but legends stop working when I start having multiple lines with different ranges (to plot a function f(x) whose definition depend on x like in the following example). I actually haven’t seen any example of this anywhere : Here the legend is ignored. I also trie…
Tag: sympy
Decimal logs in Sympy
I want to solve an expression in SymPy But then I try to code it like this The result isn’t correct. Answer You’ve got the result with ten digits, and not the decimal logarithm. Documentation says, In SymPy, as in Python and most programming languages, log is the natural logarithm, also known as l…
ModuleNotFoundError: No module named ‘sympy’
I’m on MacOSX Mojave 10.14.6 on a MacBook Pro 2015. So I pip installed sympy, right? I head over to my shell, run python3, and do: Just to be sure, I pip installed again just to make sure. My pip list also includes sympy as sympy 1.4. What’s wrong here? Is there another setup step I’ve misse…
Differential equation change of variables with sympy
I have an ordinary differential equation like this: I want to perform a variable change : How can I do this with sympy? Answer Use the following function: For the example posted: Under this substitution the differential equation outputted is then:
Extract coefficients and corresponding monomials from a given polynomial in SymPy
Given a symbolic multivariate polynomial P, I need to extract both its coefficients and corresponding monomials as lists: such that P is the dot product of coefficients and monomials, e.g., if P(x,y) = ax**2 + bxy + cy**2 then we should get coeffs = [a, b, c] and monoms = [x**2, x*y, y**2]. Getting the coeffi…
How to customize and add extra elements to Sympy plots?
I have a few questions about what how to work with graphics, using Sympy. My code: 1) The graph is obtained stretched along the x axis. How to make so that the curve looked like a circle? 2) How to add other elements to the chart. For example, the point O(0, 0) and the line y = x. Answer According
Expand index notation equation using sympy
Below I have an equation written using index notation. This equation can be expressed with the six equations on the figure. The first equation is expanded using index notation (einstein notation: https://en.wikipedia.org/wiki/Einstein_notation). In U_k,k the comma is a convention for derivative. Since we have…
How to make Polygon in SymPy from a list of vertices
I want to use SymPy to create a Polygon with n faces and calculate all parameters. The easy form is but I want to use n points from a list, for example But this form and similar is not validated. Any suggestions? Answer You could do this by putting an asterisk in front of the list of parameters to expand