Community Profile

# Jan Valdman

49 total contributions since 2010

Associate professor of applied mathematics

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

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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 ...

alrededor de 1 mes 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...

alrededor de 1 mes ago | 2 answers | 1

### 2

Submitted

Simulation of von Kármán viscoelastic plates
A quasistatic evolution of viscoelastic von Kármán plates.

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...

2 meses 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 ...

2 meses ago

Solved

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

2 meses 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...

2 meses ago

Solved

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

2 meses ago

Solved

Given a and b, return the sum a+b in c.

2 meses 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

Submitted

Implementation of C1 FEM
Detailed implementation of Bogner-Fox-Schmit elements.

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.

Submitted

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

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...

alrededor de 1 año 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...

alrededor de 1 año 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...

alrededor de 1 año ago | 1 answer | 0

### 1

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...

alrededor de 1 año 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...

alrededor de 1 año 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...

alrededor de 1 año ago

Submitted

Evolutionary model for shape memory alloys
Software for a new article - more details later

Submitted

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

Submitted

Fast FEM assembly: nodal elements
Vectorized assembly of FEM matrices.

Submitted

Fast FEM assembly: edge elements
Vectorized assembly of FEM matrices.

Submitted

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

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...

casi 2 años ago | 2 answers | 1

### 2

Submitted

Error identities for variational problems with obstacles
Calculaton of Error identities for variational problems with obstacles

Submitted

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

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...

más de 2 años 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 ...

más de 2 años ago

Solved

Triangle Numbers
Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3 which can be displa...

más de 2 años ago