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--- software:scilab:linear-algebra [2020/07/28 08:02] – [Matrix] tormec
+++ software:scilab:linear-algebra [2023/05/28 16:37] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
+====== Linear algebra ======
+===== Vector =====
+To define a column vector:
+<code>
+v = [1; 2; 3]
+</code>
+To define a row vector, two syntaxes are possible:
+<WRAP group>
+<WRAP half column>
+<code>
+v = [1 2 3]
+</code>
+</WRAP>
+<WRAP half column>
+<code>
+v = [1, 2, 3]
+</code>
+</WRAP>
+</WRAP>
+===== Matrix =====
+To define a matrix:
+<code>
+M = [1 2 3; 4 5 6; 7 8 9]
+</code>
+$$
+\begin{bmatrix}
+& 2 & 3 \\
+& 5 & 6 \\
+& 8 & 9 \\
+\end{bmatrix}
+$$
+===== Get element from vector/matrix =====
+Get element from a vector ''v'':
+  * to get element in the ''<i>''-position: <code>v(<i>)</code>
+Get element from a matrix ''M'':
+  * to get the element in the ''<i>''-row and ''<j>''-column: <code>M(<i>,<j>)</code>
+  * to get the whole ''<i>''-row: <code>M(<i>,:)</code>
+  * to get the whole ''<j>''-column: <code>M(:,<j>)</code>
+  * to get the whole ''<j>''-''<k>''-columns: <code>M(:,[<j>,<k>])</code>
+  * to get the whole ''<i>''-''<k>''-rows: <code>M([<i>,<k>],:)</code>
+===== Data structure =====
+The ''struct()'' method allows to save data in the form ''<field>, <value>''.
+===== Create data structure with a loop =====
+<code>
+g = list("g1", "g2", "g3")
+p = struct()
+for i = g
+    p(i) = i
+end
+fn = fieldnames(p)
+for j = fn'
+    disp(p(j))
+end
+</code>