Douglas Blumeyer's RTT How-To: Difference between revisions

Line 642:

<code>antiNullSpaceBasis[{{-4,-10},{4,-1},{-1,5}}]</code>

|{19,30,44}

|{{19,30,44}}

|}

Notice how when writing our comma basis in Wolfram Language, we have to write it differently than we probably would otherwise. Wolfram doesn't understand RTT's angle bracket syntax for indicating how a matrix is sliced and diced; it supports only one way of writing matrices: as lists within lists, where the outermost list is always assumed to be vertical. So if we have a comma basis with two commas, we can't just write one comma and then the other; we have to do one element from each comma in a group at a time. It's not a ~~big~~ deal, but again, may take a little getting used to.

Notice how when writing our comma basis in Wolfram Language, we have to write it differently than we probably would otherwise. Wolfram doesn't understand RTT's angle bracket syntax for indicating how a matrix is sliced and diced; it supports only one way of writing matrices: as lists within lists, where the outermost list is always assumed to be vertical. So if we have a comma basis with two commas, we can't just write one comma and then the other; we have to do one element from each comma in a group at a time. Also, note that our output is within two layers of curly brackets; this is because it's a matrix with one row, not a vector with one column. None of this is a huge deal or anything, but again, it may just take a little getting used to.

Now the null-space function, to take you from {{vector|{{map|19 30 44}}}} back to the matrix, is pretty much the same thing, but simpler! No need to anti-transpose. Just start at the augmentation step:

@@ Line 642: / Line 642: @@
 <code>antiNullSpaceBasis[{{-4,-10},{4,-1},{-1,5}}]</code>
-|{19,30,44}
+|{{19,30,44}}
 |}
-Notice how when writing our comma basis in Wolfram Language, we have to write it differently than we probably would otherwise. Wolfram doesn't understand RTT's angle bracket syntax for indicating how a matrix is sliced and diced; it supports only one way of writing matrices: as lists within lists, where the outermost list is always assumed to be vertical. So if we have a comma basis with two commas, we can't just write one comma and then the other; we have to do one element from each comma in a group at a time. It's not a big deal, but again, may take a little getting used to.
+Notice how when writing our comma basis in Wolfram Language, we have to write it differently than we probably would otherwise. Wolfram doesn't understand RTT's angle bracket syntax for indicating how a matrix is sliced and diced; it supports only one way of writing matrices: as lists within lists, where the outermost list is always assumed to be vertical. So if we have a comma basis with two commas, we can't just write one comma and then the other; we have to do one element from each comma in a group at a time. Also, note that our output is within two layers of curly brackets; this is because it's a matrix with one row, not a vector with one column. None of this is a huge deal or anything, but again, it may just take a little getting used to.
 Now the null-space function, to take you from {{vector|{{map|19 30 44}}}} back to the matrix, is pretty much the same thing, but simpler! No need to anti-transpose. Just start at the augmentation step: