Expressions

CLIPig supports expressions for all parameters. Some parameters also support variables and the expression will be evaluated every time the value is needed.

E.g., if you want thrice the CLIP-resolution of 224x224 pixels but have reasons to not calculate it, just say:

resolution: 224*3

Note: Parameters that expect lists (like resolution above) copy a single value to all entries of the list. A list can be specified with

• YAML syntax:

  resolution: 
    - 640
    - 480

• with commas:

  resolution: 640, 480

• or simply with spaces

  resolution: 640 480

  If you type expressions, you might want to use spaces or commas. In case of list parameters you'll need to use the YAML lists:

  resolution:
  - 224 * 3
  - pow(224, 1.2)

The result of an expression is automatically converted to the desired type. So even if your resolution expression generates a float it will be cast to integer before being used.

Note: Divisions through zero and stuff like this will throw an error and stop the experiment.

Expression variables

time variables

Holds variables that reference the current training time.

epoch variable

type: int

The current epoch / frame, starting at zero.

time variable

type: float

The current epoch / frame divided by the number of epochs, or in other words: A float ranging from 0.0 (start of training) to 1.0 (end of training).

time_inverse variable

type: float

One minus the current epoch / frame divided by the number of epochs, or in other words: A float ranging from 1.0 (start of training) to 0.0 (end of training).

time_step variable

type: function(float, float)

A function that returns a float in the range [0, 1] during the time interval defined by the two values.

time_step(0, 1)    # increases from zero to one during whole training
time_step(0.5, 1)  # increases from zero to one during second half of training
time_step(0.5, 0)  # decreases from one to zero during first half of training

resolution variables

Holds the resolution of the training image.

resolution variable

type: [int, int]

The resolution of the training image as list of width and height.

width variable

type: int

The width of the training image.

height variable

type: int

The width of the training image.

learnrate variables

The current values of learnrate and learnrate_scale which can be expressions themselves.

learnrate variable

type: float

The currently used learnrate

learnrate_scale variable

type: float

The currently used learnrate_scale

target feature variables

Variables available to target features

similarity variable

type: float

The cosine similarity of the CLIP-representation of the current, transformed image area with the desired feature.

The value is in the range [-100, 100].

target constraint variables

Variables available to constraints

similarity variable

type: float

The mean of all cosine similarities of the CLIP-representation of the current, transformed image area with the desired features of this target.

The value is in the range [-100, 100].