Associate professor of applied mathematics

https://sites.google.com/site/janvaldman/

Professional Interests: FEM, nonlinear computational mechanics, a posteriori error estimates, MATLAB vectorizations

Solved

Return the 3n+1 sequence for n

A Collatz sequence is the sequence where, for a given number n, the next number in the sequence is either n/2 if the number is e...

5 months ago

Answered

Minimization of a function with unknown gradient but known sparsity pattern of its hessian

Dear colleague, based on our discussions from yesterday, I implemented a finite difference scheme for a gradient approximation ...

Minimization of a function with unknown gradient but known sparsity pattern of its hessian

Dear colleague, based on our discussions from yesterday, I implemented a finite difference scheme for a gradient approximation ...

9 months ago | 0

Question

Minimization of a function with unknown gradient but known sparsity pattern of its hessian

Dear colleagues, is there a fmincon option to minimize a function without the knowledge of its gradient but providing a sparsit...

9 months ago | 2 answers | 1

Submitted

Simulation of von Kármán viscoelastic plates

A quasistatic evolution of viscoelastic von Kármán plates.

10 months ago | 3 downloads |

Solved

Pascal's Triangle

Given an integer n >= 0, generate the length n+1 row vector representing the n-th row of <http://en.wikipedia.org/wiki/Pascals_t...

10 months ago

Solved

Find the sum of all the numbers of the input vector

Find the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...

10 months ago

Solved

Determine if input is odd

Given the input n, return true if n is odd or false if n is even.

10 months ago

Solved

Count ones

Write a program to count number of ones (1s) in an integer variable input. For example: Input x=2200112231 output y=3 I...

10 months ago

Solved

Complex number

For complex number c=a+bi, write code that will add a and b together.

10 months ago

Submitted

Equilibria of economical models with cost of change

Evaluations of Cournot-Nash and Stackelber-Cournot-Nash equilibria for models with several firms using Gauss method

11 months ago | 5 downloads |

Submitted

Implementation of C1 FEM

Detailed implementation of Bogner-Fox-Schmit elements.

1 year ago | 1 download |

Submitted

Hyper elasticity with a non-penetration condition

A 2D FEM solver based on an energy minimisation formulated in C^1 deformation including a new non-penetration term.

1 year ago | 2 downloads |

Submitted

Element-based Solvers

2D Poisson's solver using only local FEM matrices without the global matrix assembly.

1 year ago | 1 download |

Solved

Finding Perfect Squares

Given a vector of numbers, return true if one of the numbers is a square of one of the other numbers. Otherwise return false. E...

1 year ago

Solved

Pizza!

Given a circular pizza with radius _z_ and thickness _a_, return the pizza's volume. [ _z_ is first input argument.] Non-scor...

1 year ago

Question

Is there any gradient descent method available?

We are working on the optimization of nonconvex energies in mechanics of solid (see the attached picture) resulting from the fin...

2 years ago | 1 answer | 0

Solved

Fibonacci sequence

Calculate the nth Fibonacci number. Given n, return f where f = fib(n) and f(1) = 1, f(2) = 1, f(3) = 2, ... Examples: Inpu...

2 years ago

Solved

Select every other element of a vector

Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

2 years ago

Solved

Interpolator

You have a two vectors, a and b. They are monotonic and the same length. Given a value, va, where va is between a(1) and a(end...

2 years ago

Submitted

Evolutionary model for shape memory alloys

Software for a new article - more details later

2 years ago | 4 downloads |

Submitted

Fast elastoplastic FEM assembly

Vectorized assembly of FEM matrices and including complete calculations of elastoplasticity benchmarks.

2 years ago | 7 downloads |

Submitted

Fast FEM assembly: nodal elements

Vectorized assembly of FEM matrices.

2 years ago | 6 downloads |

Submitted

Fast FEM assembly: edge elements

Vectorized assembly of FEM matrices.

2 years ago | 11 downloads |

Submitted

Computation of the Friedrichs and Poincare constants in 2D/3D

Computation of Friedrichs and Poincare constants in 2D/3D from generalized eigenvalue problems.

2 years ago | 1 download |

Question

Matlab Exchange - More authors to one contribution

We are three persons in a team finishing up a Matlab package to upload. I already have an account, but my colleagues not. If the...

2 years ago | 2 answers | 1

Submitted

Error identities for variational problems with obstacles

Calculaton of Error identities for variational problems with obstacles

3 years ago | 2 downloads |

Submitted

Continuum undergoing combined elasto-plasto-damage transformation.

Time-dependent evolution of the continuum undergoing combined elasto-plasto-damage transformation.

3 years ago | 3 downloads |

Solved

Determine whether a vector is monotonically increasing

Return true if the elements of the input vector increase monotonically (i.e. each element is larger than the previous). Return f...

3 years ago

Solved

Find all elements less than 0 or greater than 10 and replace them with NaN

Given an input vector x, find all elements of x less than 0 or greater than 10 and replace them with NaN. Example: Input ...

3 years ago