6.3. `strans` functions
Prev | Up | Chapter 6. Functions | Home | Next

## 6.3. `strans` functions #

### 6.3.1. Converting to ZXZ #

Using the function `strans_zxz(strans),` you can convert an Euler transformation to `ZXZ` axes transformation.

Example 6.7. Change the transformation axes to `ZXZ`

Convert the transformation `strans '20d, -270d, 70.5d, XZY'` to a `ZXZ` transformation.

    sql> SELECT strans_zxz ( strans '20d, -270d, 70.5d, XZY' );

### 6.3.2. Angles and axes #

It is possible to get the components of an Euler transformation.

Table 6.1. Getting Euler transformation attributes

function | description
--- | ---
`phi` | first angle of a transformation
`theta` | second angle of a transformation
`psi` | third angle of a transformation
`axes` | transformation axes as a three letter code

The angles will always returned as a `float8` value in radians. The axes are returned as a three letter code.

Example 6.8. Get the second axis and its rotation angle

    sql> SELECT theta( strans '20d,30d,40d,XZY' ) * 180 / pi() AS theta;
     theta
    -------
     30
    (1 row)
    sql> SELECT substring ( axes ( strans '20d,30d,40d,XZY' ) from 2 for 1 ) AS axis;
     axis
    ------
      Z
    (1 row)

Prev | Up | Next
6.2. `spoint` functions | Home | 6.4. scircle functions