User xinxin guo

9 votes

1 answer

6k views

How to define the Einstein summation convention in Mathematica?

asked Nov 13, 2012 at 12:59

9 votes

1 answer

184 views

LaplaceTransform works well with x[t], but doesn't recognize x[1][t], how to make it works for x[1][t]?

asked Jan 6, 2022 at 14:38

8 votes

3 answers

1k views

Symbolic integration in real domain only ( assumptions and ComplexExpand don't work)

asked May 13, 2013 at 10:36

8 votes

1 answer

234 views

Why can't I use logic operator Or to specify multiple events with WhenEvent?

asked Feb 19 at 3:44

7 votes

1 answer

497 views

How to implement a Kalman or LQG regulator in the control of classical pendulum problem

asked Nov 2, 2019 at 6:47

6 votes

1 answer

249 views

I understand mol but meet difficulty in understanding how `pdetoode` atumatically generate pde-to-ode-rules by using this strange pattern and rule?

asked Jan 12, 2022 at 17:52

6 votes

2 answers

140 views

Why do I get repeated points when extracting mesh points from ParametricPlot

asked May 18 at 8:15

5 votes

1 answer

314 views

How to paint a window in my house yellow? [image processing with Mathematica]

asked Mar 3 at 14:05

5 votes

2 answers

153 views

How to guide Eliminate or GroebnerBasis to reduce a set of simple odes to a single ode (which can be done by Laplace Transform)

asked Jan 6, 2022 at 13:36

5 votes

3 answers

131 views

How can I select the function and its derivative with the smallest or largest index from a list of function and function derivatives?

asked Feb 3 at 14:47

4 votes

1 answer

139 views

How to accelerate numerial inverse laplace transform for pdes of Euler-Bernoulli beam problem

asked Jan 6, 2022 at 1:53

4 votes

4 answers

220 views

Is there a way to tell FindShortestTour to avoid backtracking when connecting points to form a closed, but possiblely non-convex, curve?

asked May 21 at 8:47

4 votes

1 answer

141 views

How can I use WhenEvent to make one object (follower) follow another obect (mover) with a gap between them?

asked Sep 4 at 9:57

3 votes

1 answer

98 views

How to make pdConv not show the independent variables of functions

asked Jan 30 at 7:48

3 votes

2 answers

91 views

Why my trimmed image is blank and the imported image is so small?

asked Mar 2 at 4:03

3 votes

1 answer

217 views

How to express a periodic piecewise linear function in terms of Mod function? or linear combination of Mod?

asked Jan 24, 2022 at 13:38

2 votes

2 answers

156 views

Replacement with equivalent local variable and global variables give apparently different results using the same NDSolve output

asked Feb 6, 2022 at 11:57

2 votes

1 answer

95 views

Why doesn't the action in my code using WhenEvent option of NDSolve work?

asked Jan 20 at 7:44

2 votes

1 answer

59 views

Confusing behavior of LQR control that strongly depends on system output (with odes solved by NDSolve)

asked Nov 5, 2019 at 5:29

2 votes

1 answer

134 views

In NDSolve, how to involve in the odes a integration function that depends on ode functions and can't be analytically integrated?

asked Jun 10, 2016 at 11:37

2 votes

2 answers

725 views

Get the approximate analytical solution to an equation

asked Feb 10, 2013 at 4:41

2 votes

1 answer

421 views

Residue failed to reproduce this residue in a paper

asked Jun 17, 2016 at 7:36

2 votes

1 answer

114 views

Problem when extracting data of a closed curve from a black and white image: how to find the correct transformation of coordinates?

asked Mar 2 at 16:17

2 votes

1 answer

103 views

How to transform a tensor (for example, the second order identity tensor) or matrix from cartesian coordinates to cylindrical coordinates?

asked Mar 25 at 9:36

2 votes

1 answer

161 views

Why FindRoot gives wrong answer for the roots of a vector interpolation function

asked May 20 at 0:45

1 vote

1 answer

39 views

Unevaluated indexed variable in the events when using Table or Array generating a list of events [duplicate]

asked Sep 7 at 3:32

1 vote

1 answer

115 views

Is it possible to make an ODE-based system component that can be used repeatedly?

asked Sep 1 at 3:03

1 vote

1 answer

102 views

Strange output of a simple statespace model

asked Nov 1, 2019 at 3:27

1 vote

1 answer

351 views

A simplification of a complex expression

asked Jun 15, 2016 at 4:01

1 vote

0 answers

167 views

Problem of calculating the residue of a expression (to confirm the result from a paper) [duplicate]

asked Jun 16, 2016 at 8:13

Stack Exchange Network

35 Questions

How to define the Einstein summation convention in Mathematica?

LaplaceTransform works well with x[t], but doesn't recognize x[1][t], how to make it works for x[1][t]?

Symbolic integration in real domain only ( assumptions and ComplexExpand don't work)

Why can't I use logic operator Or to specify multiple events with WhenEvent?

How to implement a Kalman or LQG regulator in the control of classical pendulum problem

I understand mol but meet difficulty in understanding how `pdetoode` atumatically generate pde-to-ode-rules by using this strange pattern and rule?

Why do I get repeated points when extracting mesh points from ParametricPlot

How to paint a window in my house yellow? [image processing with Mathematica]

How to guide Eliminate or GroebnerBasis to reduce a set of simple odes to a single ode (which can be done by Laplace Transform)

How can I select the function and its derivative with the smallest or largest index from a list of function and function derivatives?

How to accelerate numerial inverse laplace transform for pdes of Euler-Bernoulli beam problem

Is there a way to tell FindShortestTour to avoid backtracking when connecting points to form a closed, but possiblely non-convex, curve?

How can I use WhenEvent to make one object (follower) follow another obect (mover) with a gap between them?

How to make pdConv not show the independent variables of functions

Why my trimmed image is blank and the imported image is so small?

How to express a periodic piecewise linear function in terms of Mod function? or linear combination of Mod?

Replacement with equivalent local variable and global variables give apparently different results using the same NDSolve output

Why doesn't the action in my code using WhenEvent option of NDSolve work?

Confusing behavior of LQR control that strongly depends on system output (with odes solved by NDSolve)

In NDSolve, how to involve in the odes a integration function that depends on ode functions and can't be analytically integrated?

Get the approximate analytical solution to an equation

Residue failed to reproduce this residue in a paper

Problem when extracting data of a closed curve from a black and white image: how to find the correct transformation of coordinates?

How to transform a tensor (for example, the second order identity tensor) or matrix from cartesian coordinates to cylindrical coordinates?

Why FindRoot gives wrong answer for the roots of a vector interpolation function

Unevaluated indexed variable in the events when using Table or Array generating a list of events [duplicate]

Is it possible to make an ODE-based system component that can be used repeatedly?

Strange output of a simple statespace model

A simplification of a complex expression

Problem of calculating the residue of a expression (to confirm the result from a paper) [duplicate]