Community Profile # Torsten

Last seen: Today Active since 2013

#### Statistics

• • • • • #### Content Feed

View by

Performing Chi Square Test

ongeveer 9 uur ago | 0

Substitute symbolic matrices into numerical matrices
Do you know Cramer's rule ? A = sym('A',[3 3]); b = sym('b',[3 1]); x = sym('x',[3 1]); sol = solve(A*x==b,x) And now pleas...

ongeveer 11 uur ago | 0

System of Nonlinear Equations are failing to be solved
In my opinion, it should be eq1 = C_arg + P_arg == pi-phi_m*pi/180; instead of eq1 = C_arg + P_arg == pi-phi_m*180/pi; (see ...

ongeveer 14 uur ago | 1

| accepted

Force a starting point on exponential graph
You must normalize to time = 0, not time = 24.4. The initial mass is the key, not the mass when already 24.4 (whatever) have pa...

ongeveer 14 uur ago | 0

How do I write the below code in efficient way in MATLAB?
Q = [16,32,64,128,256,512,1024]; VEC=[0.2380 0.2380 0.2380 0.2380 0.2380 0.2380 0.2380 1.1898 1....

ongeveer 16 uur ago | 0

| accepted

Limits of Euler's beta function are 0 and 1, not a and b. So C_m,i^nu = beta(i*nu+3,(m-i)*nu)/beta(i*nu,(m-i)*nu) + 2 and th...

ongeveer 17 uur ago | 0

How to solve differential equation including derivative of eigenvalue of tensor?
Following Walter's idea, this should give you a start: syms s A = sym('A',[3 3]); % Define characteristic polynomial determi...

1 dag ago | 0

How to plot 4 curves with different constants?
y = @(C,x) (C-x)./(1+x.^2); C = [1 2 3 4].'; x = -2:0.1:2; plot(x,y(C,x))

2 dagen ago | 0

Use of 'ArrayValued' in Matlab numerical integration
f = @(x) 5*ones(size(x)); integral(f,0,2)

3 dagen ago | 0

How to write a code that takes a vector and outputs true if its the same forwards as it is backwards and false if not?
https://de.mathworks.com/help/matlab/ref/flip.html answer = isequal(v,flip(v))

3 dagen ago | 1

Unable to perform assignment because the size of the left side is 360-by-1 and the size of the right side is 360-by-360.
Elementwise division is required: hip_percent(:,2) = 0.14*asis_d./hip_d + 0.5*(hip_d - asis_d)./hip_d; or simpler hip_percent...

3 dagen ago | 0

| accepted

angle function in matlab formula
It's all written in the MATLAB documentation of "angle": Algorithms angle takes a complex number z = x + iy and uses the atan2...

3 dagen ago | 1

Using anonymous functions with vectors of unknown number of elements and getting the coefficients associated with the variables
Then n_s = 2; u = randi([-9999, 9999], 1, n_s) c = sym('c',size(u)); kappa = expand((1+u*c.')^2) coefficients = coeffs(ka...

3 dagen ago | 1

| accepted

Nonlinear regression not working
clc; clear all; input0= [160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 138 137 136...

3 dagen ago | 0

| accepted

Find close points in two matrices of coordinates
Use "pdist2" to calculate the distances of the sites of the first set to the sites of the second set. Check which rows of the d...

4 dagen ago | 0

How to fasten the loop
Maybe there are faster commands than arrayfun for extracting the elements of LONG in cell arrays that correspond to sequences of...

4 dagen ago | 0

Normal random number generation
pd = makedist('Normal'); t = truncate(pd,0,1); r = random(t,1e6,1); figure(1) histogram(r,100) Or directly: r = -sqrt(2)*e...

4 dagen ago | 1

cumsum function question for integration
cumsum(y_cos*inter_val); is a Riemann sum for the integral of sin(t) - integrated between 0 and x. But the integral of sin(t) ...

4 dagen ago | 1

| accepted

I want to do exponential fitting for power decaying with time
x=[ 65.10 1.0000e+000 65.90 61.0843e-003 70.30 21.3693e-003 ]; fun = @(p)exp(-p*(x(:,1)-65.1)); f...

4 dagen ago | 0

How to define an ellipse by the eigendecomposition of its transformation matrix?
phi = linspace(0,2*pi,100); S = [1 0;0 4]; xy = S*[cos(phi);sin(phi)]; theta = pi/4; Sxy = [cos(theta) -sin(theta);sin(theta...

4 dagen ago | 2

| accepted

I have some coupled nonlinear ordinary differential equations. Three equations have three 2nd order derivative coupled together. Can someone tell me how I can get the response
Solve the third equation for theta_dotdot and insert this expression in equations (1) and (2). Then use the usual substitution...

4 dagen ago | 1

| accepted

When calling a user defined function, MATLAB throws an error for simple matrix multiplication
"const1" and "const2" are not visible in "planck_function" since you didn't declare them as "global" in the calling program. Bu...

4 dagen ago | 0

How can i use optimproblem as a free derivatives method?
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8736798

5 dagen ago | 0

how to use symsum for this problem
If you use symbolic variables, you should name them as such. And you shouldn't name a variable "sym", especially if you do symb...

5 dagen ago | 0

How to code Flux Boundary Conditions for a PDE using ODE15s and method of lines
One of many possibilities: dc/dr = 0 c2 - c1 = 0 -> dc1/dt = dc2/dt De*dc/dr = kf*(C-c) De*(cn-c(n-1))/Vl_stage = kf*(C-...

5 dagen ago | 0

| accepted

Error: Not enough input arguments
r = [2.5 1.2 0.45]; y0 = [1 1 0 1 0 0]; tspan = linspace(0,5); soltrue = ode45(@(t,y)diffun(t,y,r),tspan,y0); yvalstrue = de...

5 dagen ago | 1

| accepted

how to use derivative of function using gradient?
Add the variable "dens_mix" as an algebraic equation to your system (e.g. as y(13)): dydz(13) = y(13) - (partial_dens(1)+partia...

5 dagen ago | 1

Why fsurf show anything for my function?
Is this an explanation ? clear syms eta__2 zeta__2 Hvs2 =((2305843009213693952*(eta__2 - 8331386150863307/9007199254740992)^...

6 dagen ago | 0