Find Nearest Smaller Number in Array

Find the closest smaller value of an array

If you array is sorted, and small enough, a really simple mode to do what you want it's simplly iterate over the array until number > number-in-array then return the number on the previous position.

function getClosestValue(myArray, myValue){
    //optional
    var i = 0;

    while(myArray[++i] < myValue);

    return myArray[--i];
}

Regards.

Find nearest smaller number in array

Given that the array is sorted , You need

if let value = numbers.last(where: { $0 <= target }) {
  print(value)
}

Infer nearest, smaller value in numpy array

Using searchsorted is an option (as mentioned in the comment above and in the one of the answers in the linked question):

>>> true_values[-np.searchsorted(true_values[::-1], my_values)]
array([ 0.1,  1.2,  3. ,  4.5,  0.1,  2.4,  1.2,  3. ,  1.2])

Note that searchsorted requires the true_values to be sorted in ascending order. Here it's necessary to flip the order of your example array and then make the indices returned into negative integers for the fancy-indexing.

If true_values is not sorted (in any direction), you'll need to use np.argsort and the sorter parameter in searchsorted.

Find equal or nearest smaller value from an array

Sort the array and then do a binary search to find the values.

See:

https://en.wikipedia.org/wiki/Binary_search

and

Array.BinarySearch Method

Find nearest smaller value in Matlab

This can be done in a vectorized way as follows (note that the intermediate matrix d can be large). If there is no number satisfying the condition the output is set to NaN.

d = Triggs(:).'-Peaks(:); % matrix of pair-wise differences. Uses implicit expansion
d(d<=0) = NaN; % set negative differences to NaN, so they will be disregarded
[val, result] = min(d, [], 1); % for each column, get minimum value and its row index
result(isnan(val)) = NaN; % if minimum was NaN the index is not valid

If it is assured that there will always be a number satisfying the condition, the last line and the variable val can be removed:

d = Triggs(:).'-Peaks(:); % matrix of pair-wise differences. Uses implicit expansion
d(d<=0) = NaN; % set negative differences to NaN, so they will be disregarded
[~, result] = min(d, [], 1); % for each column, get row index of minimum value

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