CONCAT/APPEND/PREPEND CAS FUNCTION - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: CONCAT/APPEND/PREPEND CAS FUNCTION (/thread-6628.html) CONCAT/APPEND/PREPEND CAS FUNCTION - compsystems - 07-30-2016 03:08 AM CONCAT(ARG1, ARG2) FUNCTION CAS Example FIRST ARGUMENT A MATRIX OR VECTOR ARRAY or LISTS with matrix dimension (nxm) mat1 := [[a,b],[c,d]] [Enter] returns [[a,b],[c,d]] Matrix (2rowsx2cols) OK Case 1: vec1 := [[1],[2]] [Enter] returns [[1],[2]] Matrix (2rowsx1cols) or Column Vector (2 Elements) OK concat(mat1,vec1) returns [[a,b,1],[c,d,2]] Matrix (2rowsx3cols) OK Concatenates to the right, because the second argument is a column vector Case 2: vec2 := [[3,4]] [Enter] returns [[3,4]] Matrix (1rowsx2cols) or Row Vector (2 Elements) OK concat(mat1,vec2) returns [[a,b],[c,d],[3,4]] Matrix (3rowsx2cols) OK Concatenates down, because the second argument is a row vector Case 3: vec3 := [[3,4,5]] Returns [[3,4,5]] Matrix (1rowsx3cols) or Row Vector (3 Elements) OK concat(mat1,vec3) returns [[a,b]],[c,d], [3,4,5]] Concatenates down because the second argument is a row vector with more columns than the firts argument but (to put the answer to the entry line [up] [copy] show empty elements) [up] [copy] [[a,b, □],[c,d, □],[3,4,5]] Matrix (3rowsx3cols) WITH EMPTY ELEMENTS (□) RE: [Request] fill zeros in vectors and matrices with empty elements - parisse - 07-30-2016 07:51 AM concat([[a,b],[c,d]],[[3,4,5]]) returns a list of 3 lists with different sizes, it's not a matrix anymore. Your matrix arguments must have the same number of lines for matrix concatenation. RE: - compsystems - 07-30-2016 12:33 PM Another Example with CONCAT CAS FUNCTION FIRST ARGUMENT A LIST without matrix dimension, only elements Case 4: list1 := {abc, {d,e} , f} [ENTER] returns {abc, {d,e}, f} // a List with 3 Elements OK list2 := {{g,h}} [ENTER] returns {{g,h}} // a List with 1 Elements, in this case it is also a row matrix (1x2). OK concat(list1,list2) [ENTER] returns {abc,{d,e},f, {g,h} }// a List with 4 Elements OK Case 5: list3 := [abc, [d,e] , f] [ENTER] returns [abc, [d,e] , f] // a List with 3 Elements OK list4 := [[g,h]] [ENTER] returns [[g,h]] // a List with 1 Elements, in this case it is also a row matrix (1x2). OK concat(list3,list4) [ENTER] returns [abc,[d,e],f,[g,h]] // a List with 4 Elements OK Case 6: list3 := [abc, [d,e] , f] [ENTER] returns [abc, [d,e] , f] // a List with 3 Elements OK list2 := {{g,h}} [ENTER] returns {{g,h}} // ok concat(list3,list2) [ENTER] returns [abc, [d,e], f, {g,h}] // a List with 4 Elements OK Case 7: list1 := {abc, {d,e} , f} [ENTER] returns {abc, {d,e}, f} // ok list4 := [[g,h]] [ENTER] returns [[g,h]] // ok concat(list1,list4) [ENTER] returns{abc, {d,e} , f, [g,h]} // a List with 4 Elements OK RE: - compsystems - 07-30-2016 12:37 PM (07-30-2016 07:51 AM)parisse Wrote:  concat([[a,b],[c,d]],[[3,4,5]]) returns a list of 3 lists with different sizes, it's not a matrix anymore. Your matrix arguments must have the same number of lines for matrix concatenation. Here there is an error, if not is a matrix, the output should not add empty fields to copy to the entry line concat(mat1,vec3) returns [[a,b,[c,d],[3,4,5]] In the history is not displayed, but to copy to the entry line following the key sequence ([up] [copy]) if displayed the empty fields [[a,b, □],[c,d, □],[3,4,5]] RE: [Request] fill zeros in vectors and matrices with empty elements - parisse - 07-30-2016 01:33 PM It's not output, it's input, in textbook mode, it's not related to the CAS therefore I won't comment. RE: - compsystems - 07-30-2016 02:12 PM yes , now I realize. it really is another problem of COPY system function and not CONCAT CAS, copy function should check first if the output a true matrix array and then convert to template the output to the entry line should be shown as follows image RE: - compsystems - 07-30-2016 02:47 PM Now I am using the APPEND/PREPEND CAS FUNCTION, Case 1: mat1 := [[a,b],[c,d]] [Enter] returns [[a,b],[c,d]] Matrix (2rowsx2cols) OK vec0 := [[1,2]] returns [[1,2]] Matrix (1rowx2cols) or AKA Row Vector (2 Elements) OK append(mat1,vec0) returns [ [a,b], [c,d], [[1,2]] ] ok prepend(mat1,vec0) returns [ [[1,2]], [a,b], [c,d]] ok Case 2: mat1 := [[a,b],[c,d]] [Enter] returns [[a,b],[c,d]] Matrix (2rowsx2cols) OK vec1 := [[1],[2]] [Enter] returns [[1],[2]] Matrix (2rowsx1col) or AKA Column Vector (2 Elements) OK APPEND append(mat1,vec1) [Enter] returns [ [a,b], [c,d], [[1],[2]] ] OK a list of 3 elements string(append(mat1,vec1) ) [Enter] returns ""[ [a,b], [c,d], [[1],[2]]]"" OK dim(append(mat1,vec1)) [Enter] returns 3 elements OK PREPEND prepend(mat1,vec1) [Enter] returns [ [[1],[2]], [a,b], [c,d] ] ok a list of 3 elements string(prepend(mat1,vec1)) returns "[ [[1],[2]], [a,b], [c,d] ]" dim(prepend(mat1,vec1)) [Enter] returns [3,2] ??? Case 3: mat1 := [[a,b],[c,d]] [Enter] returns [[a,b],[c,d]] Matrix (2rowsx2cols) OK list5 := [1,2] [Enter] returns [1,2] List (2 Elements) OK append(mat1,list5) [Enter] returns [[a,b],[c,d],[1,2]] OK dim(append(mat1,list5)) [Enter] returns [3,2] ok prepend(mat1,list5) [Enter] returns [[1,2],[a,b],[c,d]] OK dim(prepend(mat1,list5)) [Enter] returns [3,2] ok RE: CONCAT/APPEND/PREPEND CAS FUNCTION - parisse - 07-30-2016 04:50 PM append/prepend adds an element to a list, it does not glue matrices together. RE: CONCAT/APPEND/PREPEND CAS FUNCTION - Tim Wessman - 08-01-2016 08:46 PM I don't believe there is any error here with the editor or COPY. The 2D editor doesn't allow you to skip entry of required items. The CAS might allow you to create a vector of vectors containing differing lengths, but as pointed out that is no longer a matrix. Thus when you copy it in, it correctly identifies two places with missing items. RE: CONCAT/APPEND/PREPEND CAS FUNCTION - compsystems - 08-01-2016 11:40 PM Example mat1 := [[a,b],[c,d]] [Enter] returns [[a,b],[c,d]] Matrix (2rowsx2cols) OK vec1 := [[1],[2]] returns [[1],[2]] Matrix (2rowsx1col) or AKA Column Vector (2 Elements) OK append(mat1,vec1) [Enter] returns [ [a,b], [c,d], [[1],[2]] ] OK a LIST of 3 elements but not a matrix array dim(append(mat1,vec1)) [Enter] returns 3 elements OK, Confirms that it is a list firts element: [a,b] Second: [c,d] Third: [[1],[2]] This would be the true fit to an array [ [a,b], [c,d], [1,0], [2,0] ] but not [ [a,b], [c,d], [1],[2] ] there is a problem rref(append(mat1,vec1)) [enter] "Error: Bad Argument Value" true. the NEXT matrix is a matrix wrong [ [a,b], [c,d], [1],[2] ] this is a matrix? not Simply, if the list has no matrix dimension, should not be set to a matrix, because in most cases is not feasible RE: CONCAT/APPEND/PREPEND CAS FUNCTION - Tim Wessman - 08-02-2016 04:04 PM (08-01-2016 11:40 PM)compsystems Wrote:  [ [a,b], [c,d], [1],[2] ] this is a matrix? not No, it is not. That is a vector of 2, two length vectors, and a two one item vectors. Quote:dim(prepend(mat1,vec1)) [Enter] returns [3,2] ??? Contradiction No, it isn't. You have 3 items, with a maximum size of 2 in the other direction. That does not mean you can't have fewer then 2 in a specific position. The CAS does not have a "matrix" object. It only has vectors that can contain other objects. A "matrix" is a vector of equal length vectors. Anything else is simply a vector of assorted objects. You are correct that the 2D editor does not support this type of entry. This is by design due the two simple facts that a) there are not really any direct uses for this type of object in the various math commands - it is only really useful during programming and b) to support it would mean making the 2D editor allow this type of input which is detrimental to nearly every single user.