symbolic-math

For the purposes of what I want to do I need to take a user input as a string and convert it into an unevaluated function. For example, if the user input was "x^2*sin(x)" I would need a function that took a double input x and returned Math.Pow(x, 2)*Math.Sin(x) I need the function, I can't pass in a value for x and I will be calling the function many times (hundreds possibly) so I can't parse the string each time I am making a calculation. How would I implement this? I take it from the question Convert a string into mathematical equation? that there is not a standard way to do this. But I am a

How can I make a function from a symbolic expression? For example, I have the following: syms beta n1,n2,m,aa= Constants u = sqrt(n2-beta^2); w = sqrt(beta^2-n1); a = tan(u)/w+tanh(w)/u; b = tanh(u)/w; f = (a+b)*cos(aa*u+m*pi)+a-b*sin(aa*u+m*pi); %# The main expression If I want to use f in a special program to find its zeroes, how can I convert f to a function? Or, what should I do to find the zeroes of f and such nested expressions? You have a couple of options... Option #1: Automatically generate a function If you have version 4.9 (R2007b+) or later of the Symbolic Toolbox you can convert a

According to wiki : In mathematics and computer science, computer algebra, also called symbolic computation or algebraic computation is a scientific area that refers to the study and development of algorithms and software for manipulating mathematical expressions and other mathematical objects Does symbolic computation focus on symbol manipulation and computation? Lisp program is written in the form of an AST with atoms as leaves. Lisp is said to be language for symbolic computing. Does it mean that in symbolic computation, it is: all about symbols (symbols are atoms or non-atom expressions in

I have some expressions such as x^2+y^2 that I'd like to use for some math calculations. One of the things I'd like to do is to take partial derivatives of the expressions. So if f(x,y) = x^2 + y^2 then the partial of f with respect to x would be 2x , the partial with respect to y would be 2y . I wrote a dinky function using a finite differences method but I'm running into lots of problems with floating point precision. For example, I end up with 1.99234 instead of 2 . Are there any libraries that support symbolic differentiation? Any other suggestions? I've implemented such libraries in

So im using MATLAB to calculate the coefficient of an equation and it keeps displaying fractions as the constants instead of decimal form like xxe-x My code is below bt = 0.03175; bpzt = 0.0078; ht = 0.003; w = 50; % frequency in Hz pnic = 8908; % density of nickel Enic = 200e9; % Young's modulus of nic L = 0.3048; % Length of canitlever beam in m syms hn inertia = (1/12)*bt*ht^3 + (1/2)*bpzt*ht^2*hn - (1/2)*bpzt*ht*hn^2 + (2/3)*bpzt*hn^3 area = (bt*ht - 2*hn*bt + 2*bpzt*hn); You are using the symbolic math toolbox. You have to convert any symbolic variable back to a numerical one. Use double

When I type import sympy as sp x = sp.Symbol('x') sp.simplify(sp.log(sp.exp(x))) I obtain log(e^x) Instead of x . I know that "there are no guarantees" on this function. Question. Is there some specific simplification (through series expansion or whatsoever) to convert logarithm of exponent into identity function? You have to set x to real type and your code will work: import sympy as sp x = sp.Symbol('x', real=True) print(sp.simplify(sp.log(sp.exp(x)))) Output: x . For complex x result of this formula is not always is equal to x . Example is here . If you want to force the simplification,

Here is my Matlab program: syms x(t) t; f = x^2 + 5; And the result of f : f(t) = x(t)^2 + 5 Both f and x are of class symfun in Matlab. I want the result of df/dx, which is equal to 2*x(t) . I tried this in Matlab: diff(f, x); and got the following errors: Error using mupadmex Error in MuPAD command: The variable is invalid. [stdlib::diff] Error in sym/diff (line 57) R = mupadmex('symobj::diff', S.s, x.s, int2str(n)); How can df/dx be obtained in Matlab? In newer versions of Matlab (I'm using R2014b) the error message is clearer: Error using sym/diff (line 26) All arguments, except for the