shalnivardhan asked . 2020-09-03

How can I plot a symbolic function or determine a finite and real starting guess for fzero?

I have a very long and somewhat complicated complex function that I need to find the roots of. It is a function of "s", which is imaginary, and which I had to define as a symbol in order to work through previous steps and get the function (Functionofs). For those interested in the background math, I am trying to solve the characteristic equation from a determinant of a 4x4 matrix made from a transfer function made from the equations of motion of a beam. When I try starting guesses that I think would make sense using the fzero command, I keep getting the error "Function value at starting guess must be finite and real." I have tried the following:
1) Tried substituting values using subs(Functionofs,s,1*i) to see if I could happen upon something that would work. It just finished (after several minutes) and gave me an extremely long (output truncated) expression with fractions, etc. Does not seem to be of any use. I used simplify(ans) and got it down to a manageable (sort of) size, but it is still a symbol- can I convert this back to a decimal number or expression somehow?
2) Tried to plot Functionofs, but received an error that SYM could not be converted to DOUBLE to plot.
Does anyone have any ideas on what else I could try or how to get around these errors? I have not found a way to convert a symbol to a decimal number- is there one?

matlab , plot , plotting

Expert Answer

John Williams answered . 2024-12-21 17:01:24

If you have a function of one variable, you can use my newtzero to try to find some roots. You will have to convert to a function handle first.
For example:
 
syms s
f = s.^(2*cos(s)) -s.^3 - sin(s)+1;  % Say this is your function.
% Now to find the roots.
G = matlabFunction(f);  % Convert to func handle.
newtzero(G)  % Can use no or real or imaginary guess.

years =

     0.4192 - 0.7229i
     0.4192 + 0.7229i
     1.0584          
    -0.4221 - 1.2644i
    -0.4221 + 1.2644i
    -0.2607 - 1.8053i
     1.7397 - 1.5257i
    -4.5851 - 0.7860i

As far as the plotting goes, just use the function handle returned in G above.


Not satisfied with the answer ?? ASK NOW

Frequently Asked Questions

MATLAB offers tools for real-time AI applications, including Simulink for modeling and simulation. It can be used for developing algorithms and control systems for autonomous vehicles, robots, and other real-time AI systems.

MATLAB Online™ provides access to MATLAB® from your web browser. With MATLAB Online, your files are stored on MATLAB Drive™ and are available wherever you go. MATLAB Drive Connector synchronizes your files between your computers and MATLAB Online, providing offline access and eliminating the need to manually upload or download files. You can also run your files from the convenience of your smartphone or tablet by connecting to MathWorks® Cloud through the MATLAB Mobile™ app.

Yes, MATLAB provides tools and frameworks for deep learning, including the Deep Learning Toolbox. You can use MATLAB for tasks like building and training neural networks, image classification, and natural language processing.

MATLAB and Python are both popular choices for AI development. MATLAB is known for its ease of use in mathematical computations and its extensive toolbox for AI and machine learning. Python, on the other hand, has a vast ecosystem of libraries like TensorFlow and PyTorch. The choice depends on your preferences and project requirements.

You can find support, discussion forums, and a community of MATLAB users on the MATLAB website, Matlansolutions forums, and other AI-related online communities. Remember that MATLAB's capabilities in AI and machine learning continue to evolve, so staying updated with the latest features and resources is essential for effective AI development using MATLAB.

Without any hesitation the answer to this question is NO. The service we offer is 100% legal, legitimate and won't make you a cheater. Read and discover exactly what an essay writing service is and how when used correctly, is a valuable teaching aid and no more akin to cheating than a tutor's 'model essay' or the many published essay guides available from your local book shop. You should use the work as a reference and should not hand over the exact copy of it.

Matlabsolutions.com provides guaranteed satisfaction with a commitment to complete the work within time. Combined with our meticulous work ethics and extensive domain experience, We are the ideal partner for all your homework/assignment needs. We pledge to provide 24*7 support to dissolve all your academic doubts. We are composed of 300+ esteemed Matlab and other experts who have been empanelled after extensive research and quality check.

Matlabsolutions.com provides undivided attention to each Matlab assignment order with a methodical approach to solution. Our network span is not restricted to US, UK and Australia rather extends to countries like Singapore, Canada and UAE. Our Matlab assignment help services include Image Processing Assignments, Electrical Engineering Assignments, Matlab homework help, Matlab Research Paper help, Matlab Simulink help. Get your work done at the best price in industry.