Community Profile

# per isakson

### KTH

2.253 total contributions since 2010

View all

Contributions in
View by

Analyze this %% x=[1,2,3,4,5,6,7,8,9,10,11,12]; % x values y=[15,120,2,30,40,150,60,170,80,9,15,1000]; % y values %% idx1 =...

etwa 3 Stunden ago | 1

| accepted

Are enum-comparisons slow in MATLAB?
Indeed, enumerations make slow code. This is an anecdote about a code based on enumeration that proved useless because of poor...

etwa 9 Stunden ago | 0

Basic queries Matlab (vectors, indexing, construct matrices in a specific form)
Exercise 1 and 2 "[...] however it confuses me the way the question is written!" Agree; the very same vector has three differe...

3 Tage ago | 0

keep element greater than immediate previous element
An alternative %% x = [1 2 3 4 3 2 3 4 6 8 5 5 6 8.5 9 11 12 ]; %% dx = 1; while not( isempty( dx ) ) dx = fin...

3 Tage ago | 1

How to reduce computation time
On R2018b and a new vanilla PC I found a significant decrease in computation time by replacing quad2d() by integral2() (with the...

3 Tage ago | 1

How can I write a variable which datatype is a string in netcdf file
Most likely, the space you specified for the variable calibration_procedure in the nc-file, i.e. 'Dimensions',{'hydrophone_cou...

3 Tage ago | 0

| accepted

constructing a difficult large matrix
Here are three functions, two of which are based on the answer of David Goodmanson. I think all of them are fast enough. However...

4 Tage ago | 1

Randomly convert exact number of 1 to 0 in binary matrix
Try %% x = [ 0 1 0 1 0 1 1 1 1]; %% ix_one = find( x == 1 ); ix_set_zero = randi( numel(ix_one), 1,2 ); x( ...

5 Tage ago | 0

| accepted

number permutate without permutation
Steps to find a substitute for perms without perms Lookup perms in the documenttion, perms, All possible permutations See "Se...

5 Tage ago | 0

is 2GB RAM ok for MATLAB 2020 ?
Yes, you don't need to install Polyspace, but plain Matlab requires a minimum of 4GB. See System Requirements for MATLAB R2020a

6 Tage ago | 0

| accepted

Storing data from a loop
Pre-allocate Y1 and Y2 Assign to elements of Y1 and Y2 Do not change the loop counter, ii, in the loop The documentation say...

6 Tage ago | 0

I am having problems with my homework:Write a function called valid_date that takes three positive integer scalar inputs year, month, day....
Replace (rem(year,4)==0 && rem(year,100)~=0) || (rem(year,400)==0 && rem(year,100)~=0) by (rem(year,4)==0 && rem(year,100)~=...

7 Tage ago | 0

cellfun vs. varfun applied to column of table
This works, but may contain more code than you hoped for. %% T = table({'147956, 154414'; '1, 7439'; '93053, 101815'; '50151, ...

7 Tage ago | 1

OPP using any algorithm
Did you check YALMIP and MATPOWER ?

8 Tage ago | 0

Continuing an input function onto another line
The documentation says; The start and end quotation marks for a character vector must appear on the same line. For example, thi...

10 Tage ago | 0

export codes written in editor into word
See Bring along your syntax highlighted code and M2HTML: Documentation System for MATLAB in HTML

10 Tage ago | 1

| accepted

Transaction Data in HTML file
This is a start %% sad = dir( 'd:\m\cssm\transData*.txt' ); len = length( sad ); out = cell( len, 2 ); for jj = 1 : len ...

12 Tage ago | 0

| accepted

Textscan with '@' as delimiter
I've reproduced your result on R2018b. The result is according to the textscan documentation - I think. out1 is a cell array of...

15 Tage ago | 0

| accepted

Converting txt file into title and array?
Try this %% fid = fopen( 'cssm.txt', 'rt' ); xL = fgetl( fid ); % read the first line data = fscanf( fid, '...

15 Tage ago | 0

| accepted

Updating a Property in an Array of Objects
The documentation doesn't tell that a statement like [WorkOrder(1,:,1).nid] = listData.nid(:,1); isn't possible. You are not t...

15 Tage ago | 0

| accepted

apply function to all fields in a structure array
Another mix of structfun and arrayfun >> max( cell2mat( arrayfun( @(S) structfun( @(f) f, S.F1 ), sa, 'uni',false ) ), [], 2 ) ...

16 Tage ago | 0

| accepted

Preallocation of a matrix: how to shrink it afterwards?
Something like this fullstate = class_of_state( size(epochn) ); for t = reshape( epochn, 1,[] ) idx = find(epochn == t); ...

16 Tage ago | 0

How to read only some columns of a text file?
The text file might have more than 7 coloums. Replace '%*n %*n %n %n %n %n %n' by '%*s%*s%n%n%n%n%n%*[^\n]' %*[^\n]' ski...

16 Tage ago | 0

how to control the length of indexed array element?
"(from 1 to the last bit of m(i)) " Here is my shot in the dark %% m = uint8([1,2,3,4]); len = length(m); m_d = 0.5*...

17 Tage ago | 0

| accepted

anonymous function with a variable number of input variables
"anonymous function with a variable number of input variables" Something like this? >> ht(1,2,3) ans = 6 >> ht(1,2,3,4...

18 Tage ago | 1

Replace readtable('filename.xls'); by readtable( [ filename, '.xls' ] ); to use the value of the variable not its name.

18 Tage ago | 1

| accepted

How to use R2020a import tool to upload multiple excel files
YES! See Import or Export a Sequence of Files and How can I process a sequence of files?

18 Tage ago | 1

convert matrix data to cell array data
Try this >> num2cell( magic(5), 1 ) ans = 1×5 cell array Columns 1 through 4 {5×1 double} {5×1 double} {5×1 d...

19 Tage ago | 0

| accepted

how do I store an array of functions?
An error message tells me Nonscalar arrays of function handles are not allowed; use cell arrays instead. Is this what are loo...

19 Tage ago | 0