CODEWITHSUNDEEP
r
user9798936
user9798936

Reputation:

How to find the length of a list based on a condition in R

The problem

I would like to find a length of a list.

The expected output

I would like to find the length based on a condition.

Example

Suppose that I have a list of 4 elements as follows:

myve <–list(1,2,3,0)

Here I have 4 elements, one of them is zero. How can I find the length by extracting the zero values? Then, if the length is > 1I would like to substruct one. That is:

If the length is 4 then, I would like to have 4-1=3. So, the output should be 3.

Note

Please note that I am working with a problem where the zero values may be changed from one case to another. For example, For the first list may I have only one 0 value, while for the second list may I have 2 or 3 zero values.

The values are always positive or zero.

Upvotes: 0

Views: 679

Answers (2)

Pop
Pop

Reputation: 12411

You just need to apply the condition to each element. This will produce a list of boolean, then you sum it to get the number of True elements (i.e. validation your condition).

In your case:

sum(myve != 0)

In a more complex case, where the confition is expressed by a function f:

sapply(myve, f)

Upvotes: 2

K.Hua
K.Hua

Reputation: 799

Use sapply to extract the ones different to zeros and sum to count them

sum(sapply(myve, function(x) x!=0))

Upvotes: 0

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