# TI-BASIC:List Frequency2

**Routine Summary**

Returns a list of the frequency of values in another list sorted.

**Inputs**

*L₁* - the list you want to find the frequency of

**Outputs**

*L₂* - the values of L₁ without repetition sorted
*L₃* - the frequencies of the values in the list L₂ sorted

**Variables Used**

L₁, L₂, L₃, θ

**Calculator Compatibility**

TI-83/84/+/SE
**Author**

Galandros*URL:* United TI
**Download**

:DelVar L₂DelVar L₃SortA L₁ :For(θ,1,dim(L₁ :L₁(θ→L₂(1+dim(L₂ :sum(L₁=Ans→L₃(dim(L₂ :θ-1+Ans→θ :End

In the first line we initialize L₁, L₂, and L₃. We sort L₁ so like values will be adjacent.

Then we start looping by storing the first value encountered to the next element of list L₂. In the next line we find the frequency of the value already stored in L₂ and is stored to the correspondent element in L₃. θ is increased by the frequency found minus 1 to pass to next number, but then incremented by 1 in the For loop. We loop we reach the end of L₁.

And that's it. The output is put on L₂ and L₃ already sorted. Notice how well Ans is used for speed and size optimization.

When you are done using L₁, L₂, and L₃, you should clean them up at the end of your program.