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1. Matlab return index of nonzero elements how to#
2. Matlab return index of nonzero elements code#
3. Matlab return index of nonzero elements trial#

I also really don't think this is the best strategy, since the max chain in my data will be tens of thousands of values.

Matlab return index of nonzero elements how to#

I am sure this is a relatively simple thing to do so I was hoping someone could offer insight.ĮDIT: Here's what I tried: s = zeros(size(x1)) įor a vector x1 which has a max chain of 72 but I dont know how to find the max chain and return its first value, so I know where to trim. I need to get rid of these rows before I can start analyzing the movement from the trials.

Matlab return index of nonzero elements trial#

I am working with movement data from a joystick and there are a few thousand rows of data with a mix of zeros and nonzero values before the actual trial begins (coming from subjects slightly moving the joystick before the trial actually started). This explains the algorithm.I am trying to write a simple MATLAB program that will find the first chain (more than 70) of consecutive nonzero values and return the starting value of that consecutive chain. We can again typecast it to a list and print the new list. NumPy provides us with a nonzero() method which returns a tuple of arrays containing indices of the nonzero elements. Then we convert the given list into a numpy array as shown below. We can also access non-zero elements of a list using numpy. Li_new = Īs you can see, the program returns indices for the non-zero elements. For an arbitrary sized matrix x, how do I find the index of the last non-zero element in each row of a given matrix For example, for the matrix. This corresponds to location 1 of the augmented data matrix, so you can match them up by adding 1 to the index. The missing dates will return an index of zero, since theyre missing. data find Find indices and values of nonzero elements fliplr Flip elements of input array or matrix. Then, you find the time index locations of the actual times you have in the master list of all times. We are also using list comprehension to keep it short. 1001 tips to speed up MATLAB programs Yair M. function y nonzero (u) x find (u) will return index of non-zero elements.

Matlab return index of nonzero elements code#

If you don’t know about the enumerate() method, do give it a read: Enumerate() Method in Python Also, find function will return the index of the non zero elements in a vector, so if you want values at the index, you can code in the following way: Theme. MATLAB Language Fundamentals Matrices and Arrays Creating and Concatenating Matrices. Now i would like to make the sum of the nonzero-elements between the zeros.example. Hallo everybody i have a vector with zeros and nonzero-entries. In this method, we are using the enumerate() method to convert the list into iterable. Learn more about sum, elements, nonzero, vector, index.

first create array X so as for even number in v X is one and zero for the others : X (mod (v,2)0) then use find to find desired indices : idxevenfind (X) Share. This is a shorthand implementation of the above algorithm. k find (X) returns a vector containing the linear indices of each nonzero element in array X. Using enumerate() and list comprehensionĪnother way to find the indices of the non-zero elements is the method followed in the given example program. find (X) returns a vector containing the linear indices of each nonzero element in array X. li = Īs it’s clear from the output, the list has non-zero values at indexes 0, 2, 3 and 5. We have done this implementation in the following program. Well, if we want to find the index of non-zero elements of a list, we can use a for loop to iterate the list and store the index values in a different list.

We can use the following methods in such cases.

There may be instances when we need to access only the non-zero elements in the list. In this tutorial, we are going to see how to find indices of the non-zero elements in the Python list.