Answered
Convert cartesian coordinates to polar coordinates
Edit your file - you did not declare it as a function, so Matlab uses it as a script. Also think about to vectorize your code, t...

5 years ago | 2

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Answered
Creating a symbolic array
>> q = sym('q', [5, 5]) q = [ q1_1, q1_2, q1_3, q1_4, q1_5] [ q2_1, q2_2, q2_3, q2_4, q2_5] [ q3_1, q3_2, q3_3, q3_4...

5 years ago | 0

Answered
I'm getting an error "Undefined function 'Romberg' for input arguments of type 'char'." I'm trying to code the romberg integration method.
For me it worked: a = 0; b = pi; nmax = 3; fun ='sin (x)' ; [t, r]= Romberg (fun, a, b, nmax) function[t , r] = Romberg...

5 years ago | 0

Answered
Is it possible to solve the equation for x?
syms x a(1) = 0.89; a(2) = 6.7; a(3) = 26.12; a(4) = 0.07; a(5) = 78.05; a(6) = 34.01; a(7) = 0.33; a(8) = 22.49; a(9) ...

5 years ago | 0

Answered
Fill a vector with two vectors
V1 = [3 8 6 7] V2 = [1 5 9 4] V = reshape([V1;V2],1,[]) V = V(3:end) results in: V1 = 3 8 6 7 V2 =...

5 years ago | 1

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Answered
Trying to plot this curve what have I done wrong?
fun = @(x)(18*sqrt(2)*(sqrt(1+1./(1+x.^2)) + asin(1./(1+x.^2)-pi/2))) fplot(fun)

5 years ago | 0

Answered
How to find the solution of inverse function ?
x = [1 2 3 4 5 6 7]; y = [3.6 1.8 1.2 0.9 0.72 1.5 0.51429]; p = polyfit(x,y,2) syms x fx(x) = poly2sym(p) gx(x) = finvers...

5 years ago | 0

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Answered
Possible combinations for a vector
You could use allcomb from FEX: k = 0:2; coms = allcomb(k,k,k,k,k,k,k,k,k); as expected there are 3^9 = 19683 results

5 years ago | 1

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Answered
how do i write a matlab script to sum this expression?
Symbolic: syms n positive integer N = 10000; eq = 1/n + 1/((n+2)*(n+3)); pretty(eq) sol = symsum(eq,n,1,N) sol_num = doubl...

5 years ago | 1

Answered
ODE Function time output
Use events: Z0 = 6; Zt=0.05*6; tspan = [0 24]; opts = odeset('Events',@(tZ,Z)EventsFcn(tZ,Z,Zt)); [tZ,Z,tZe,Ze,iZe] = ode45...

5 years ago | 0

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Answered
Why isn't my code graph anything.
Try: %create a cater plot clear all; %x = [20,30,40,50] x = [-3,-1,1,2] y = [8,23,28,34] y=[8,23,28,34].' colum = [...

5 years ago | 0

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How find symbolic solution matlab
It appears that there either is no symbolic solution or Matlab is not powerful enough to find one. For sin(t) it would work. How...

5 years ago | 1

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ode 45 and for loop
k = 0; T_sol = cell(1,100); X_sol = cell(1,100); for ii = 0.1:0.1:10 k = k+1; [T,X] = ode45(@(t,x)fx(t,x,ii), [0 ...

5 years ago | 0

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Answered
Graph Plotting the differential equation
yyaxis left fplot(qSol,[0, 100]) yyaxis right fplot(TSol,[0, 100])

5 years ago | 1

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Answered
Defining function file of ODE function
C0 = 5; tspan = [0 10]; [t,C] = ode45(@Conc,tspan,C0); plot(t,C) function dCdt=Conc(t,C) k1=0.7; Vo=1; Q=Vo; Cin=200; ...

5 years ago | 1

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Answered
How do i plot this quadratic graph?
x = -10:10; y = polyval([1 -2 -4],x); plot(x,y) r = roots([1 -2 -4]) text(r(1),0,'\leftarrow Root') text(r(2),0,'\leftarrow...

5 years ago | 0

Answered
Solve a Matrix equation
Symbolic approach: A = sym('A', [4,1]) B = magic(4) P = 13 sol = solve(A'*B*A==P, A) sol.A1 sol.A2 sol.A3 sol.A4 % This...

5 years ago | 0

Answered
Suppose that at any given time t (in seconds) the current i (in amperes) in an alternating current circuit is i = 2 cos t + 2 sin t. What is the peak current for this circuit (largest magnitude)?
Do the same as shown in your question before. Then use diff(...) == 0 to find extremum points. The solve function maybe helpfu...

5 years ago | 1

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Answered
unable to find symbolic solution
1. The condition for the second ode is invalid - i assume you meant: cond = T(R)==T0; instead of cond = q(R)==T0; 2. As...

5 years ago | 1

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Answered
Find intersection point between u(t) = t^2(t-1) and u = 10.
Simply use the function you calculated: >> t_sol = vpasolve(uSol == 10,t) ans = ...

5 years ago | 1

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Answered
Error using evalin Undefined function or variable 'x'. Error in sym/eval (line 11) s = evalin('caller',vectorize(map2mat(char(x))));
clear AC=0.15; BC=0.2; AD=0.35; xA=0; yA=0; rA=[xA yA 0]; xC=AC; yC=0; rC=[xC yC 0]; syms xBsol yBsol ii=0; for ph...

5 years ago | 1

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Answered
find the equation of tangent to the curve y=2(x^1/2) at (1,2)
https://de.mathworks.com/help/symbolic/syms.html#buoeaym-1 https://de.mathworks.com/help/symbolic/diff.html

5 years ago | 1

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Answered
How to find the solution for the system of equations
Your system is inconstistent and therefore there is no solution: % x is shorter than lambda x = sym('x', [14 1]) ; % system...

5 years ago | 0

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Answered
How can I delete even rows in a matlab Matrix
>> A = [1 2 3; 4 5 6; 7 8 9; 0 -1 -2] A = 1 2 3 4 5 6 7 8 9 0 -1 -2 ...

5 years ago | 0

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Answered
ode45 Two Variable Differential equation Problem - Too many inputs error
Fixed the input in your functin. Rising t>7 gives warning, since the problem appears to be stiff: %% Initial Conditions: % Ini...

5 years ago | 0

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Answered
Graphing using Matlab. How would you graph a function using matlab?
a = 24; b = 4.8; ii = 0:20; y = a + b.*ii; plot(ii,y)

5 years ago | 0

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Please explain what this error is...
Your function has to be called with 2 inputs a and b for example when a=2 and b=5: [res1, res2, res3] = MyFun(2, 5)

5 years ago | 0

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Can anyone help me fix that error please
You missed to define several variables, which are used in your equations: % several used variables are not defined! - i set the...

5 years ago | 0

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fsolve with one variabel
Tinc = 5+273; Tinv = 45+273; mv = 1000; Cpv = 4180; A = 0.032*(21-2); h = 20; U = ...

5 years ago | 2

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Find the value which causes an error from a vector
This works with logical indexing, therefore avoids the if / else logic and should ensure that you do not need any error messages...

5 years ago | 0