1. Symbolic substitution - MATLAB subs
Subs - Symbolic substitution
This MATLAB function returns a copy of s, replacing all occurrences of old with new, and then evaluates s.
2. Evaluate Symbolic Expressions Using subs - MATLAB & Simulink
When you assign a value to a symbolic variable, expressions containing the variable are not automatically evaluated. Instead, evaluate expressions by using subs ...
Evaluate expressions and functions after their variables are assigned values.
3. subs (Symbolic Math Toolbox)
subs(S) replaces all occurrences of variables in the symbolic expression S with values obtained from the calling function, or the MATLAB workspace.
Symbolic substitution in a symbolic expression or matrix.
4. Substitute Variables in Symbolic Expressions - MATLAB & Simulink
Use the subs function to replace k by a in the solution vector solx, parameters params, and conditions conds.
Substitute variables with other variables, numbers, vectors, or matrices.
5. Substitute Elements in Symbolic Matrices - MATLAB & Simulink
Use subs to substitute the element of B by specifying the variable name. For example, substitute B2_2 with 4. B = subs(B,B2_2,4).
Substitute elements in symbolic matrices.
6. MATLAB: subs, eval - learnonline
You can use the general subs command g=subs(f,old,new) which in our cases would be g=subs(f,x,c) or g=subs(f,x,x0). Here old, new can
See Also12445 East Caley AvenueVariable substitution and expression evaluation: subs, eval Suppose you have a symbolic expression f which includes the symbol x and you wish to substitute for x another symbol c or a numerical value x0. Then you can use the general subs command g=subs(f,old,new) which in our cases would be g=subs(f,x,c) or g=subs(f,x,x0). Here old, new can be arrays. The result g is still a symbolic variable or symbolic constant in “Maple”. Example 1: Consider a function of the two Cartesian coordinates f(x, y) = 2xy/(x2 + y2)2 . Change to polar coordinates using x = r cos θ, y = r sin θ and then determine the value of f at an arbitrary point on the unit circle r = 1. clear all syms x y r theta f=2*x*y/(x^2+y^2)^2; F=subs(f,[x y],[r*cos(theta) r*sin(theta)]); F=simple(F) % previous answer is messy f_on_unit_circle=subs(F,r,1) which gives the output F=sin(2*theta)/r^2 f_on_unit_circle=sin(2*theta) An alternative is to use the eval command. It is of the form ans=eval(S) where S is a symbolic expression for which at least one of its symbolic variables has just been given a value. If all variables are given numerical values, the answer is a number in MATLAB, not “Maple”. Example 2: Let us compare simple MATLAB and “Maple” codes which both evaluate the expression y = (x3 + 2) sec x at x = 0.123. MATLAB code Maple code using subs Maple code using eval clear all clear all clear all x=0.123 syms x syms x y=(x^3+2)*sec(x) S=(x^3+2)*sec(x); S=(x^3+2)*sec(x); y=subs(S,x,0.123) x=0.123; y...
7. subs a value from gpu to a symbolic function - MATLAB Answers
22 aug 2023 · I am trying to substitute some symbolic variables in a symbolic function with some values from GPU. However, the subs function recognise ...
I am trying to substitute some symbolic variables in a symbolic function with some values from GPU. However, the subs function recognise these values as 0s as shown in the code below: syms q1 q2 ...
8. How to substitute multiple array syms easily? - MATLAB Answers
12 okt 2019 · subs() can accept an array of variables as its second parameter, and another array the same size as the third parameter, and does a substitution ...
Setup: A = sym('A', 4) B = sym('B', 3) x = A*A(1:4,1)+[B(1:3,1); 0] subs(x, {A, B}, {diag([3,2,1,0]), diag([1,3,5])}) Output: A = [ A1_1, A1_2, A1_3, A1_4] [ A2_1, A2_2, A2_3, A2_4] ...
9. speed up "subs" function or faster alternative ways for symbolic ...
5 jun 2023 · When I used "subs" function to substitute the symbolic variables, it took around 0.03 seconds for 1 matrix. This is relatively slow because I ...
I am simulating a robotic system with symbolic dynamic matrices of the robot. When I used "subs" function to substitute the symbolic variables, it took around 0.03 seconds for 1 matrix. This is rel...
10. Subs Command for Multivariable Function - MATLAB Answers
7 feb 2020 · The question I am trying to solve is to evaluate that function at x & y are equal to the listed values using the subs command and by conversion into a matlab ...
syms x y g=(1/2)*e^(-2*x/3).*tan(y+1); subs(g,x,0.3); subs(g,y,-0.7);
