Array1D class
This class provides utility functions for 1D arrays (vectors):
- adding arrays with various options
- Finding the minimum or maximum values with various options
- splitting, shuffling, swapping, extracting given index ranges
Constructors
- Array1D()
Properties
- hashCode → int
-
The hash code for this object. [...]
read-only, inherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
Methods
-
integ_trapez(
Float64List array, int firstix, int lastix, double bias, double slope) → Float64List -
Computes a new array representing the integral function of
array
in the specified range.array
represents the values of a function at equidistant x coordinates.firstix
first index inarray
to contribute to integral.lastix
last index inarray
to contribute to integral. Returns the integral function computed fromfirstix
untillastix
with index increment 1. The last value in the returned array is the integral value over the entire region. [...] -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
-
toString(
) → String -
Returns a string representation of this object.
inherited
Operators
-
operator ==(
dynamic other) → bool -
The equality operator. [...]
inherited
Static Properties
Static Methods
-
addArrays(
Float64List a1, Float64List a2, int type) → Float64List -
Returns the index-wise sum of
a1
anda2
according totype
:type
= POS: adds the positive or zero values ofa1
anda2
onlytype
= NEG: adds the negative or zero values ofa1
anda2
onlytype
= POSNEG: normal add of all values Application: Building "projections". -
getMax(
Float64List array) → List -
Finds the maximum value of the numbers in
array
.array
may contain null values, they are skipped. Returnsthe maximum, its index
. If 2 maxima with the same value exist, the 1st one is returned. -
getMaxInRange(
Float64List arr, int firstIx, int lastIx) → double -
Finds the maximum value of the numbers in
array
in the range fromfirstIx
tolastIx
, both indices inclusive. Both indices may have the values null (at the same time), the the entirearray
is searched.array
may contain null values, they are skipped. Returns the maximum, if 2 maxima with the same value exist, the 1st one is returned. -
getMaxInRangeStep(
Float64List array, int startix, int endix, int incr) → List -
Finds the maximum value of the numbers in
array
in the range fromfirstIx
, inclusive, toendix
, exclusive.incr
is an index increment. If, e.g.,incr
==1, only every second array element is considered.array
may contain null values, they are skipped. Returnsthe maximum, its index
. If 2 maxima with the same value exist, the 1st one is returned. -
getMaxIntPos(
List< int> array) → List<int> -
Finds the positive-valued maximum value of the numbers in
array
, assuming thatarray
] contains values >= 0.array
may contain null values, they are skipped. Returnsthe maximum, its index
. If 2 maxima with the same value exist, the 1st one is returned. -
getMin(
Float64List array) → List -
Finds the minimum value of the numbers in
array
.array
may contain null values, they are skipped. Returnsthe minimum, its index
. If 2 minima with the same value exist, the 1st one is returned. -
getMinInRange(
Float64List array, int startix, int endix, int incr) → List -
Finds the minimum value of the numbers in
array
in the range fromfirstIx
, inclusive, toendix
, exclusive.incr
is an index increment. If, e.g.,incr
==1, only every second array element is considered.array
may contain null values, they are skipped. Returnsthe minimum, its index
. If 2 minima with the same value exist, the 1st one is returned. -
getMinMaxVals(
Float64List array) → List< double> -
Returns a pair of doubles which are the max and min values contained in
array
, in the following order:min, max
ormax, min
depending on whether min occurs before max in the array, or the other way around. -
getMinVal(
Float64List array) → double -
Returns the minimum value of the numbers in
array
. -
getRow(
Float64List array, int row, int nrows) → Float64List -
Considers
array
as a two-dimensional array withnrows
rows. The rows, when appended to each other in sequence, are building uparray
. Returns a new array consisting of the rowrow
whose length will be (array.length / nrows). Returns null ifrow
outside range. Conditions: row >= 0. If array.length cannot be divided by nrows without a remainder, the repective part ofarray
can't be obtained.array
will remain unmodified. -
isPowerOfTwo(
int n) → bool -
Returns true if
n
is a power of 2. -
nextPowerOfTwo(
int n) → int - Returns a number which: [...]
-
rotate(
Float64List array, int n) → void -
Rotates
array
to the right byn
positions in place. For example, with n = 3, the array1,2,3,4,5,6,7
is rotated to5,6,7,1,2,3,4
. -
shuffle(
Float64List a1, Float64List a2) → Float64List -
Merges the arrays
a1
anda2
to a new array "result" with double size. The even indices of "result" will be filled witha1
, the odd ones ofa2
.a1
anda2
must have the same length. See also method unshuffle. -
splitArray(
Float64List array, int size) → List< Float64List> -
Makes a 2D array from
array
. Each row of the 2D array will havesize
elements. The last row may be smaller if the length ofarray
can't be divided bysize
without remainder. Ifsize
is 0 or equal or greater than the length ofarray
, the result will containarray
as its single row. -
swap(
Float64List array) → void -
Inverts the order of
array
in place. Reverses the order ofarray
in place. Example:1,2,3,4,5,6,7,8,9,10
=>10,9,8,7,6,5,4,3,2,1
See also method swapHalf. -
swapHalf(
Float64List array) → void -
Reverses the order of the first half and the second half of
array
in place. Example:1,2,3,4,5,6,7,8,9,10
=>5,4,3,2,1,10,9,8,7,6
. See also method swap. -
swapHalfStr(
List< String> array) → void -
Inverts the order of the first half and the second half of
array
in place. -
swapStr(
List< String> array) → void -
Inverts the order of
array
in place. -
unshuffle(
Float64List array) → List< Float64List> -
Makes 2 arrays "resultArray" (of half length) from
array
: resultArray0
consists of the even indices ofarray
. resultArray1
consists of the even indices ofarray
. Application:array
represents a sequence complex numbers:real, imag, real, imag, ....
. Then: resultArray0
is the real part:real, real, ...
, resultArray1
is the imaginary part:imag, imag, ...
. See also method shuffle. -
zeroFill(
Float64List array, int newLength, bool zeroFillExtend) → Float64List -
Zero-fills
array
as follows and returns the result: [...]