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The Maxima on-line user's manual

Algebra Calculator

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Delete Calculator

Delete

Function: delete (<expr_1>, <expr_2>)

Function: delete (<expr_1>, <expr_2>, <n>) delete(<expr_1>, <expr_2>) removes from <expr_2> any arguments of its top-level operator which are the same (as determined by "=") as <expr_1>. Note that "=" tests for formal equality, not equivalence. Note also that arguments of subexpressions are not affected.

<expr_1> may be an atom or a non-atomic expression. <expr_2> may be any non-atomic expression. delete returns a new expression; it does not modify <expr_2>.

delete(<expr_1>, <expr_2>, <n>) removes from <expr_2> the first <n> arguments of the top-level operator which are the same as <expr_1>. If there are fewer than <n> such arguments, then all such arguments are removed.

Examples:

Removing elements from a list.

          (%i1) delete (y, [w, x, y, z, z, y, x, w]);
          (%o1)                  [w, x, z, z, x, w]

Removing terms from a sum.

          (%i1) delete (sin(x), x + sin(x) + y);
          (%o1)                         y + x

Removing factors from a product.

          (%i1) delete (u - x, (u - w)*(u - x)*(u - y)*(u - z));
          (%o1)                (u - w) (u - y) (u - z)

Removing arguments from an arbitrary expression.

          (%i1) delete (a, foo (a, b, c, d, a));
          (%o1)                     foo(b, c, d)

Limit the number of removed arguments.

          (%i1) delete (a, foo (a, b, a, c, d, a), 2);
          (%o1)                    foo(b, c, d, a)

Whether arguments are the same as <expr_1> is determined by "=". Arguments which are equal but not "=" are not removed.

          (%i1) [is (equal (0, 0)), is (equal (0, 0.0)), is (equal (0, 0b0))];

rat replaced 0.0 by 0/1 = 0.0 rat replaced 0.0B0 by 0/1 = 0.0B0

          (%o1)                  [true, true, true]
          (%i2) [is (0 = 0), is (0 = 0.0), is (0 = 0b0)];
          (%o2)                 [true, false, false]
          (%i3) delete (0, [0, 0.0, 0b0]);
          (%o3)                     [0.0, 0.0b0]
          (%i4) is (equal ((x + y)*(x - y), x^2 - y^2));
          (%o4)                         true
          (%i5) is ((x + y)*(x - y) = x^2 - y^2);
          (%o5)                         false
          (%i6) delete ((x + y)*(x - y), [(x + y)*(x - y), x^2 - y^2]);
                                        2    2
          (%o6)                       [x  - y ]

There are also some inexact matches for delete. Try ?? delete to see them.

(%o1)                                true
(%i2) 

Delete Example

Related Examples

delete-every-full_listify-lambda-listify-makelist-map-mod-primep-set_partitions-sort-sublist

p:sublist(makelist(k,...

s:makelist([(k-mod(k,...

s:map(lambda([x],dele...

Calculate

delete-ifactors-member-random-true

joukko:[30, 42, 70];

luku: joukko[random(3)];

factors_only: true;

Calculate

delete-first-lambda-map

map(lambda([x], lambd...

Calculate

delete-every-full_listify-lambda-listify-makelist-map-mod-primep-set_partitions-sort-sublist

p:sublist(makelist(k,...

s:makelist([(k-mod(k,...

s:map(lambda([x],dele...

Calculate

delete-divisors-length

atijd :divisors(50);

atijd : delete(50,ati...

atijd : delete(1,atijd);

Calculate

delete

delete(%pi, [0, 3.141...

Calculate

delete-ifactors-member-random-true

joukko:[30, 42, 70];

luku: joukko[random(3)];

factors_only: true;

Calculate

delete-ifactors-member-random-true

joukko:[30, 42, 70];

luku: joukko[random(3)];

factors_only: true;

Calculate

delete-divisors

atijd :divisors(50);

atijd : delete(50,ati...

atijd : delete(1,atijd);

Calculate

delete-load-matrix

load (lsquares);

delete(B,lsquares_est...

Calculate