expyriment.stimuli.Line¶

class expyriment.stimuli.Line(start_point, end_point, line_width, colour=None, anti_aliasing=None)¶

A class implementing a line stimulus.

__init__(start_point, end_point, line_width, colour=None, anti_aliasing=None)¶

Create a line between two points.

Parameters:	start_point(int, int) start point of the line (x,y) end_point(int, int) end point of the line (x,y) line_widthint width of the plotted line colour(int, int, int), optional line colour (int, int, int) anti_aliasingint, optional anti aliasing parameter (good anti_aliasing with 10)

property absolute_position¶

Getter for absolute_position.

Notes

The absolute position differs for instance from the (relative) position, if the stimulus is plotted ontop of another stimulus, which has not the position (0,0).

add_noise(grain_size, percentage, colour)¶

Add visual noise on top of the stimulus.

This function might take very long for large stimuli.

Parameters:	grain_sizeint size of the grains for the noise percentageint percentage of covered area colour(int, int, int) colour (RGB) of the noise
Returns:	timeint the time it took to execute this method

Notes

Depending on the size of the stimulus, this method may take some time to compute!

property anti_aliasing¶: Getter for anti_aliasing.

blur(level)¶

Blur the stimulus.

This blurs the stimulus, by scaling it down and up by the factor of ‘level’.

Parameters:	levelint level of bluring
Returns:	timeint the time it took to execute this method

Notes

Depending on the size of the stimulus, this method may take some time to compute!

clear_surface()¶

Clear the stimulus surface.

Surfaces are automatically created after any surface operation (presenting, plotting, rotating, scaling, flipping etc.) and preloading. If the stimulus was preloaded, this method unloads the stimulus. This method is functionally equivalent with unload(keep_surface=False).

Returns:	timeint the time it took to execute this method

Notes

Depending on the size of the stimulus, this method may take some time to compute!

property colour¶: Getter for colour.

compress()¶

“Compress the stimulus.

This will create a temporary file on the disk where the surface of the stimululs is written to. The surface will now be read from the disk to free memory. Compressed stimuli cannot do surface operations! Preloading comressed stimuli is possible and highly recommended. Depending on the size of the stimulus, this method may take some time to compute!

Returns:	timeint the time it took to execute this method

copy()¶

Deep copy of the visual stimulus.

Returns:	copydeep copy of self

Notes

Depending on the size of the stimulus, this method may take some time to compute!

decompress()¶

Decompress the stimulus.

This will decompress the stimulus. The surface will now be read from memory again. Depending on the size of the stimulus, this method may take some time to compute!

Returns:	timeint the time it took to execute this method

distance(other)¶

Surface center distance.

This method computes the distance between the surface center of this and another visual stimulus.

Parameters:	otherstimulus the other visual stimulus
Returns:	distfloat distance between surface centers

property end_point¶: Getter for end_point.

flip(booleans)¶

Flip the stimulus.

This is a surface operation. After this, a surface will be present!

Parameters:	booleans(bool, bool) booleans to flip or not
Returns:	timeint the time it took to execute this method

Notes

Depending on the size of the stimulus, this method may take some time to compute!

get_connecting_shape(other_line, sharp_corner=False)¶

returns a modified line shape that connects without gap with another line, if the two lines do indeed touch each other. Otherwise, a runtime error is raised.

Parameters:	other_linestimuli.Line the other line to join with sharp_cornerboolean (optional) if True, corner will be sharp and not cropped
Returns:	shapestimuli.Shape Shape representation of the modified line

Examples

>>> line_1 = stimuli.Line((100,100), (140, 190), line_width=20,
>>>                       colour=misc.constants.C_BLUE)
>>> line_2 = stimuli.Line((140, 190), (260, 230), line_width=20,
>>>                       colour=misc.constants.C_BLUE)
>>> line1_mod = line_1.get_connecting_shape(line_2, sharp_corner=False)

>>> #plot
>>> bl = stimuli.BlankScreen()
>>> line_2.plot(bl)
>>> line_1.plot(bl)
>>> bl.present()
>>> exp.keyboard.wait()

>>> bl = stimuli.BlankScreen()
>>> line_2.plot(bl)
>>> line1_mod.plot(bl)
>>> bl.present()
>>> exp.keyboard.wait()

get_pixel_array()¶

Return a 2D array referencing the surface pixel data.

Returns:	pixel_array: Pygame.PixelArray a 2D array referencing the surface pixel data

Notes

see also set_surface

property has_surface¶: Getter for has_surface.

property id¶: Getter for id.

inside_stimulus(stimulus, mode='visible')¶

Check if stimulus is inside another stimulus.

Parameters:	stimulusexpyriment stimulus the other stimulus modemode (str), optional “visible”: based on non-transparent pixels or “surface”: based on pixels in pygame surface (default = visible”)
Returns:	outbool

Notes

Depending on the size of the stimulus, this method may take some time to compute!

property is_compressed¶: Getter for is_compressed.

property is_preloaded¶: Getter for is_preloaded.

property line_width¶: Getter for line_width.

property logging¶: Getter for logging.

move(offset)¶

Moves the stimulus in 2D space.

Parameters:	offsetlist, optional translation along x and y axis
Returns:	timeint the time it took to execute this method

Notes

When using OpenGL, this can take longer then 1ms!

overlapping_with_position(position, mode='visible', use_absolute_position=True)¶

Check if stimulus is overlapping with a certain position.

Parameters:	position(int, int) position to check for overlapping modemode (str), optional “visible”: based on non-transparent pixels or “rectangle”: based on pixels in pygame surface (default = visible”) use_absolute_positionbool, optional use absolute_position of stimulus (default) instead of position
Returns:	overlappingbool

Notes

Depending on the size of the stimulus, this method may take some time to compute!

CAUTION: Please note that if a stimulus is plotted on another smaller stimulus, such that it is not fully visible on screen, this method will still check overlapping of the full stimulus! Due to a current bug in Pygame, we can right now not change this.

overlapping_with_stimulus(stimulus, mode='visible', use_absolute_position=True)¶

Check if stimulus is overlapping with another stimulus.

Parameters:	stimulusexpyriment stimulus the other stimulus modemode (str), optional “visible”: based on non-transparent pixels or “surface”: based on pixels in pygame surface (default = visible”) use_absolute_positionbool, optional use absolute_position of stimuli (default) instead of position
Returns:	overlappingbool are stimuli overlapping or not overlap(int, int) the overlap (x, y) in pixels. If mode is ‘surface’, the argument will always be None.

Notes

Depending on the size of the stimulus, this method may take some time to compute!

CAUTION: Please note that if a stimulus is plotted on another smaller stimulus, such that it is not fully visible on screen, this method will still check overlapping of the full stimulus! Due to a current bug in Pygame, we can right now not change this.

picture()¶

Return the stimulus as Picture stimulus.

This will create a temporary file on the hard disk where the image is saved to.

Notes

Depending on the size of the stimulus, this method may take some time to compute!

plot(stimulus)¶

Plot the stimulus on the surface of another stimulus.

Use this to plot more than one stimulus and to present them at the same time afterwards by presenting the stimulus on which they were plotted on.

Parameters:	stimulusexpyriment stimulus stimulus to whose surface should be plotted
Returns:	timeint the time it took to execute this method

Notes

Depending on the size of the stimulus, this method may take some time to compute!

property polar_position¶: Getter for the position in polar coordinates (radial, angle[degrees])

property position¶: Getter for position.

preload(inhibit_ogl_compress=False)¶

Preload the stimulus to memory.

This will prepare the stimulus for a fast presentation. In OpenGL mode this method creates an OpenGL texture based on the surface of the stimulus. When OpenGL is switched off, this method will create a surface if it doesn’t exists yet. If stimuli are not preloaded manually, this will happen automatically during presentation. However, stimulus presentation will take some time then!

Always preload your stimuli when a timing accurate presentation is needed!

Parameters:	inhibit_ogl_compressbool, optional inhibits OpenGL stimuli to be automatically compressed (default=False)
Returns:	timeint the time it took to execute this method

Notes

Depending on the size of the stimulus, this method may take some time to compute!

present(clear=True, update=True, log_event_tag=None)¶

Present the stimulus on the screen.

This clears and updates the screen automatically. When not preloaded, depending on the size of the stimulus, this method can take some time to compute!

Parameters:

clearbool, optional: if True the screen will be cleared automatically (default = True)
updatebool, optional: if False the screen will be not be updated automatically (default = True)
log_event_tagnumeral or string, optional: if log_event_tag is defined and if logging is switched on for this stimulus (default), a summary of the inter-event-intervalls are appended at the end of the event file

Returns:

timeint: the time it took to execute this method

reposition(new_position)¶

Move stimulus to a new position.

When using OpenGL, this can take longer then 1ms!

Parameters:	new_positiontuple (x,y) translation along x and y axis
Returns:	timeint the time it took to execute this method

Notes