# TorMec

### Sidebar

software:scilab:linear-algebra

# Linear algebra

## Vector

To define a column vector:

v = [1; 2; 3]

To define a row vector, two syntaxes are possible:

v = [1 2 3]
v = [1, 2, 3]

## Matrix

To define a matrix:

M = [1 2 3; 4 5 6; 7 8 9]

$$\begin{bmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \\ \end{bmatrix}$$

## Get element from vector/matrix

Get element from a vector v:

• to get element in the <i>-position:
v(<i>)

Get element from a matrix M:

• to get the element in the <i>-row and <j>-column:
M(<i>,<j>)
• to get the whole <i>-row:
M(<i>,:)
• to get the whole <j>-column:
M(:,<j>)
• to get the whole <j>-<k>-columns:
M(:,[<j>,<k>])
• to get the whole <i>-<k>-rows:
M([<i>,<k>],:)

## Data structure

The struct() method allows to save data in the form <field>, <value>.

## Create data structure with a loop

g = list("g1", "g2", "g3")
p = struct()

for i = g
p(i) = i
end

fn = fieldnames(p)
for j = fn'
disp(p(j))
end