Community Profile # Qian Feng

Last seen: 5 giorni ago Active since 2016

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Using vpaintegral to calculate integrations.
clear all tic my = 2; d = 15; de = 15; r1 = 2; r2 = 4.05; r3 = r2 - r1; dai1 = d+1; dai2 ...

oltre 4 anni ago | 2 answers | 0

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Question

Problem of calculating the value of integrals
Hi there, I encounter the problem of calculating the value of integrals, the code is given as follows: r1 = 2; r2 = 4; r3 ...

oltre 4 anni ago | 1 answer | 0

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Question

Implementation of Clausen function
Hi there, I wonder if I can implement the expression of Clausen functions Cl_(2k+1) and CL_(2k+2) (see the details in https://e...

oltre 4 anni ago | 0 answers | 0

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Question

How to substitute tf('s') variables into a symbolic expression
I am dealing with the following problem. syms y z r = 1; n = 3; A1 = rand(n); A2 = rand(n); A3 = rand(n); A4 = rand(n)...

circa 5 anni ago | 2 answers | 0

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Question

Using kron() function within LMI toolbox environment
Hi there, How do we implement a Kronecker product kron() within the LMI toolbox environment ? I have searched the syntax of LM...

circa 5 anni ago | 0 answers | 0

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sigma function plot of an unstable system
I encountered the following problem when I applied the sigma function to plot the frequency response of a system. clear al...

circa 5 anni ago | 1 answer | 0

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Question

Numerical sensitivity of X'*Y*X given X is a permutation matrix
Assume X is an arbitrary matrix and Y is a symmetric matrix with double floating-point format. I understand that the product X'*...

circa 5 anni ago | 1 answer | 0

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Question

Square root of a matrix
I encountered a problem when I try to compute the square root of a positive definite matrix syms x real mi = [1; exp(x); ...

circa 5 anni ago | 1 answer | 0

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Question

Rational power of a positive definite matrix
q = sym([4 2 ; 2 4]); f = sqrtm(q)^(-1) - sqrtm(q^(-1)); f should be zero here since q is positive definite. However,...

oltre 5 anni ago | 1 answer | 0

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Question

Precise conversions from double to symbolic
I have the following number r = 1.78503 I want to obtain the exact symbolic representation of 1/r, and I applied p = ...

oltre 5 anni ago | 3 answers | 0

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Question

Numerical sensitivity of function kron(X,Y)
Assume X and Y are both symmetric matrices with double floating-point format. Can kron(X,Y) potentially become asymmetric due to...

oltre 5 anni ago | 2 answers | 1

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Question

Floating point numeric problem
I encounter a problem which I cannot understand. a = 1.228269:0.000001:1.22828; b = 1.228265:0.000001:1.22828; ismembe...

oltre 5 anni ago | 1 answer | 0

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Question

Numerical values of integrals
I am dealing with a problem of finding accurate numerical values of integrals. Specifically, the integral is introduced by using...

oltre 5 anni ago | 2 answers | 0

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Question

How to convert symbolic expressions to transfer functions
I am encountering the problem of converting a symbolic expression to become a transfer function. Specifically, the linear system...

oltre 5 anni ago | 2 answers | 0