Module util

A wide variety of utility procedures and classes.

Classes
	Pose Represent the x, y, theta pose of an object in 2D space
	Point Represent a point with its x, y values
	Transform Rotation and translation represented as 3 x 3 matrix
	Line Line in 2D space
	LineSeg Line segment in 2D space
	SymbolGenerator Generate new symbols guaranteed to be different from one another Optionally, supply a prefix for mnemonic purposes Call gensym("foo") to get a symbol like 'foo37'

Functions

valueListToPose(values)
Returns: a corresponding util.Pose

localToGlobal(pose, point)
Same as pose.transformPoint(point)

localPoseToGlobalPose(pose1, pose2)
Applies the transform from pose1 to pose2

inversePose(pose)
Same as pose.inverse()

globalToLocal(pose, point)
Applies inverse of pose to point.

globalPoseToLocalPose(pose1, pose2)
Applies inverse of pose1 to pose2.

globalDeltaToLocal(pose, deltaPoint)
Applies inverse of pose to delta using transformDelta.

sum(items)
Defined to work on items other than numbers, which is not true for the built-in sum.

within(v1, v2, eps)
Returns: True if v1 is with eps of v2

nearAngle(a1, a2, eps)
Returns: True if a1 is within eps of a2.

nearlyEqual(x, y)
Like within, but with the tolerance built in

mm(t1, t2)
Multiplies 3 x 3 matrices represented as lists of lists

fixAnglePlusMinusPi(a)
A is an angle in radians; return an equivalent angle between plus and minus pi

fixAngle02Pi(a)
Returns: return an equivalent angle between 0 and 2 pi

reverseCopy(items)
Return a list that is a reversed copy of items

dotProd(a, b)
Return the dot product of two lists of numbers

argmax(l, f)
Returns: the element of l that has the highest score

argmaxWithVal(l, f)
Returns: the element of l that has the highest score and the score

argmaxIndex(l, f=<function <lambda> at 0x11bbdb0>)
Returns: the index of l that has the highest score

argmaxIndices3D(l, f=<function <lambda> at 0x11bbe30>)

randomMultinomial(dist)
Returns: random draw from that distribution

clip(v, vMin, vMax)
Returns: If vMin <= v <= vMax, then return v; if v < vMin return vMin; else return vMax

sign(x)
Return 1, 0, or -1 depending on the sign of x

make2DArray(dim1, dim2, initValue)
Return a list of lists representing a 2D array with dimensions dim1 and dim2, filled with initialValue

make2DArrayFill(dim1, dim2, initFun)
Return a list of lists representing a 2D array with dimensions dim1 and dim2, filled by calling initFun(ix, iy) with ix ranging from 0 to dim1 - 1 and iy ranging from 0 to dim2-1.

make3DArray(dim1, dim2, dim3, initValue)
Return a list of lists of lists representing a 3D array with dimensions dim1, dim2, and dim3 filled with initialValue

mapArray3D(array, f)
Map a function over the whole array.

makeVector(dim, initValue)
Return a list of dim copies of initValue

makeVectorFill(dim, initFun)
Return a list resulting from applying initFun to values from 0 to dim-1

prettyString(struct)
Make nicer looking strings for printing, mostly by truncating floats

prettyPrint(struct)

gensym(prefix='i')
Call this function to get a new symbol

logGaussian(x, mu, sigma)
Log of the value of the gaussian distribution with mean mu and stdev sigma at value x

gaussian(x, mu, sigma)
Value of the gaussian distribution with mean mu and stdev sigma at value x

lineIndices((i0, j0), (i1, j1))
Takes two cells in the grid (each described by a pair of integer indices), and returns a list of the cells in the grid that are on the line segment between the cells.

lineIndicesConservative((i0, j0), (i1, j1))
Takes two cells in the grid (each described by a pair of integer indices), and returns a list of the cells in the grid that are on the line segment between the cells.

findFile(filename)
Takes a filename and returns a complete path to the first instance of the file found within the subdirectories of the brain directory.

Variables
	__package__ = `None`

Function Details

valueListToPose(values)

Parameters:

values - a list or tuple of three values: x, y, theta

Returns:

a corresponding util.Pose

localToGlobal(pose, point)

Same as pose.transformPoint(point)

Parameters:

point - instance of util.Point

localPoseToGlobalPose(pose1, pose2)

Applies the transform from pose1 to pose2

Parameters:

pose1 - instance of util.Pose
pose2 - instance of util.Pose

inversePose(pose)

Same as pose.inverse()

Parameters:

pose - instance of util.Pose

globalToLocal(pose, point)

Applies inverse of pose to point.

Parameters:

pose - instance of util.Pose
point - instance of util.Point

globalPoseToLocalPose(pose1, pose2)

Applies inverse of pose1 to pose2.

Parameters:

pose1 - instance of util.Pose
pose2 - instance of util.Pose

globalDeltaToLocal(pose, deltaPoint)

Applies inverse of pose to delta using transformDelta.

Parameters:

pose - instance of util.Pose
deltaPoint - instance of util.Point

within(v1, v2, eps)

Parameters:

v1 - number
v2 - number
eps - positive number

Returns:

True if v1 is with eps of v2

nearAngle(a1, a2, eps)

Parameters:

a1 - number representing angle; no restriction on range
a2 - number representing angle; no restriction on range
eps - positive number

Returns:

True if a1 is within eps of a2. Don't use within for this, because angles wrap around!

fixAngle02Pi(a)

Parameters:

a - angle in radians

Returns:

return an equivalent angle between 0 and 2 pi

argmax(l, f)

Parameters:

l - List of items
f - Procedure that maps an item into a numeric score

Returns:

the element of l that has the highest score

argmaxWithVal(l, f)

Parameters:

l - List of items
f - Procedure that maps an item into a numeric score

Returns:

the element of l that has the highest score and the score

argmaxIndex(l, f=<function <lambda> at 0x11bbdb0>)

Parameters:

l - List of items
f - Procedure that maps an item into a numeric score

Returns:

the index of l that has the highest score

randomMultinomial(dist)

Parameters:

dist - List of positive numbers summing to 1 representing a multinomial distribution over integers from 0 to len(dist)-1.

Returns:

random draw from that distribution

clip(v, vMin, vMax)

Parameters:

v - number
vMin - number (may be None, if no limit)
vMax - number greater than vMin (may be None, if no limit)

Returns:

If vMin <= v <= vMax, then return v; if v < vMin return vMin; else return vMax

mapArray3D(array, f)

Map a function over the whole array. Side effects the array. No return value.

lineIndicesConservative((i0, j0), (i1, j1))

Takes two cells in the grid (each described by a pair of integer indices), and returns a list of the cells in the grid that are on the line segment between the cells. This is a conservative version.