Split an array in more part depending of a comparison

[RebeccaCasadio]

Hi to everyone, 

I have a problem. 

Starting from 2 arrays I would like to split one based on the values of the second one. 

Ex. A= [ 1 2 3 4 5 6 7 8 9 10] B = [ 3 8 ] 

Result arrays wanted:  C = [ 1 2 3] D= [ 4 5 6 7 8] E=[ 9 10 ]

The lengths of the two array are variable.  

Do you have any suggestions? 

Thank you so much in advance. 

Rebecca 

[GerdW]

Hi Rebecca,

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@RebeccaCasadio wrote:

Starting from 2 arrays I would like to split one based on the values of the second one. 

Ex. A= [ 1 2 3 4 5 6 7 8 9 10] B = [ 3 8 ] 

Result arrays wanted:  C = [ 1 2 3] D= [ 4 5 6 7 8] E=[ 9 10 ]

Do you have any suggestions? 

---

And what are the specification for splitting array A? What should be done with those values from array B?

I guess you want to split array A when there is an element "3", then split again for an element "8" and then keep the remaining elements.

What happens when the element from array B is not found in array A?

What happens when array B contains a "3", but array A contains either "2.9999" or "3.0001"?

So provide a clear (and senseful) description of the requirements and you are halfway done with solving your problem… 😄

[RebeccaCasadio]

Hi, 

I simplified the question. 

In the real program that I'm writing: 

- I have one array containing the latitude coordinates of a route: array A.

- I have an array B where there are one or more latitudes of the route (latitude coordinates in this array are not identical to the ones in array A, this is why I need to make a comparison). 

What I want to do is to compare the latitude coordinates of A with the ones in B and if their difference is lower than a threshold of 5*10^-6, I want to split the array A according to the latitude coordinates stored in array B. 

What happens when the element from array B is not found in array A? Array A remains whole, so it is not divided.

I guess you want to split array A when there is an element "3", then split again for an element "8" and then keep the remaining elements. Right 

What should be done with those values from array B? After using the array values, they are no longer used. So they are only useful for understanding how to divide array A.

I hope I’ve made myself clear.

Thanks

Reb

[GerdW · Accepted solution]

Hi Rebecca,

---

@RebeccaCasadio wrote:

What I want to do is to compare the latitude coordinates of A with the ones in B and if their difference is lower than a threshold of 5*10^-6, I want to split the array A according to the latitude coordinates stored in array B. 

---

So you want to do:

FOR i := each element in array B
  difference := arrayA - B[i]
  boolArray := (difference <= 5u)
  index := Search1DArray(boolArray, TRUE)
  IF index >= 0 THEN
    arrayA1 := ArraySubset(arrayA, 0, index+1)
    arrayA := ArraySubset(arrayA, index+1)
  ENDIF
NEXT

See how far you get with your homework stuff! 😄

(You need an autoindexing FOR loop with a shift register, some simple math/comparison, a case structure, some basic array functions…)

Hint: as your subarrays will/can have different length you should learn about using arrays of clusters of arrays!

[RebeccaCasadio]

Yes, exactly 🙂 Thank you for the answer.

My problem was (and I think is) in the implementation. But I will try. 

Thanks for your availability. 

Reb