HP Prime: adding an entry to a vector

[Alberto Candel]

Hi,

How do you add an entry to a vector (like going from [1,2] to [1,2,3])? ADDCOL for matrices does not work for vectors because (row) vectors are not matrices for the Prime (a matrix has at least 2 rows). And even if ADDCOL worked, it would not add an entry at the end of the vector.

Thank you!

Edited: 1 Dec 2013, 2:09 p.m. after one or more responses were posted

[Terje Vallestad]

I think append will do it

Example:

append([1,2,3],4) gives [1,2,3,4]

Cheers,

Terje

[cyrille de Brébisson]

ADDROW(vector, value, column) will do what you want...

cyrille

[Alberto Candel]

Thanks Terje and Cyrille,

APPEND does what I wanted, ADDROW does not seem to work ADDROW([1,2],3,3) results in error. Same with ADDCOL.

[Terje Vallestad]

Hi,

From exprimentation and seeing other similar issues by others On this forum I think you need to enclose the 3 in tickmarks.

I.e.

ADDROW([1,2],'3',3) results in [1,2,3]

ADDCOL([1,2],'3',3) also results in [1,2,3]

Cheers,

Terje

[Michael de Estrada]

What I've found is that you can't use matrix operations on a vector. A vector is designated by a single set of square brackets, e.g. [1,2,3], whereas a single row matrix will be [[1,2,3]]. If you do Shift 4 (Matrix), you will see the vector appear as dimension 3, whereas the matrix will appear as 1X3.

[Alberto Candel]

Yes, a matrix in the prime must have at least 2 rows, according to the user guide. The commands ADDCOL([1,2],'3',3) do not seem to work for me. Thanks.

[Michael de Estrada]

It doesn't need two rows; it just needs two separate dimensions. So if you have a vector v:=[1,2,3], then v(2) would return 2, whereas in a matrix m:=[[1,2,3]], m(1,2) would return 2.

Edited: 2 Dec 2013, 1:54 p.m.

[Terje Vallestad]

Hi,

I got it to work in Home, not in CAS

Cheers,

Terje

[Alberto Candel]

Ok, yes, it does work in Home. I was in CAS. thanks.

[Terje Vallestad]

Hi,

I think you will find if you try using the additional argument enclosed in tick marks, you keep the vector format in the result even if you are using matrix commands

Cheers,

Terje

[Michael de Estrada]

But why go to all this trouble ? If you just stick with matrix form throughout, everything works fine and can be done in both Home and CAS view. Just like whenever I use CAS operations inside programs, which is basically the same as Home view, then I just place them inside a CAS(" ") command.

Edited: 2 Dec 2013, 12:37 p.m.

[Alberto Candel]

Oh well, now I got it!

This works ADDCOL([[1,2]],[3],3) gives [1,2,3] in CAS.

Thank you all!