Programmer Guide/Command Reference/EVAL/complex arithmetic: Difference between revisions

From STX Wiki
Jump to navigationJump to search
No edit summary
Line 8: Line 8:
====complex numerical objects====
====complex numerical objects====
:* A complex number or complex scalar is a numerical object ''v'' with 2 rows and 1 column (a vector):
:* A complex number or complex scalar is a numerical object ''v'' with 2 rows and 1 column (a vector):
:::{|class="keinrahmen"
::{|class="keinrahmen"
|-
|-
|''v''[0] = || ''re'' (cartesian: real part) or ''len'' (polar: length)
|''v''[0] = || ''re'' (cartesian: real part) or ''len'' (polar: length)
Line 15: Line 15:
|}
|}
:* A complex vector with N elements is a numerical object ''v'' with 2N rows and 1 column (a vector):
:* A complex vector with N elements is a numerical object ''v'' with 2N rows and 1 column (a vector):
:::{|class="keinrahmen"
::{|class="keinrahmen"
|-
|-
|''v''[2*i] = || ''re''<sub>i</sub> or ''len''<sub>i</sub>
|''v''[2*i] = || ''re''<sub>i</sub> or ''len''<sub>i</sub>
Line 22: Line 22:
|}
|}
:* A complex matrix with MxN elements is a numerical object ''v'' with 2N rows and M columns (a matrix):
:* A complex matrix with MxN elements is a numerical object ''v'' with 2N rows and M columns (a matrix):
:::{|class="keinrahmen"
::{|class="keinrahmen"
|-
|-
|''v''[2*i,j] = || ''re''<sub>i,j</sub> or ''len''<sub>i,j</sub>
|''v''[2*i,j] = || ''re''<sub>i,j</sub> or ''len''<sub>i,j</sub>

Revision as of 09:27, 8 April 2011


Because the current version of the STx EVAL command do not support a complex data type, a package of functions is used to implement arithmetic and special handling for complex numbers.

The package consists of the following functions:

cr2p, cp2r, conj, cr2len, cr2phi, cget, cset, conj, cmul, ctrn, cdot, cmulv

complex numerical objects

  • A complex number or complex scalar is a numerical object v with 2 rows and 1 column (a vector):
v[0] = re (cartesian: real part) or len (polar: length)
v[1] = im (cartesian: imaginary part) or phi (polar: phase)
  • A complex vector with N elements is a numerical object v with 2N rows and 1 column (a vector):
v[2*i] = rei or leni
v[2*i+1] = imi or phii
  • A complex matrix with MxN elements is a numerical object v with 2N rows and M columns (a matrix):
v[2*i,j] = rei,j or leni,j
v[2*i+1,j] = imi,j or phii,j
  • In general a numerical object containing N x M complex numbers (N>=1, M>=1), consists of 2N rows and M columns, because each complex number uses two cells of a row.
  • If a numerical object containing N x M complex numbers, is converted element-wise to real, the resulting object consists of N x M real numbers.

complex->complex

xc ... any complex type
rc .. ... same complex type as xc
rc=cr2p(xc)
Convert xc from cartesian (real, imaginary) to polar (length, phase) format.
rc=cp2r(xc)
Convert xc from polar (length, phase) to cartesian (real, imaginary) format.
rc=conj(xc)
Conjugate xc; xc must be in cartesian format.

complex->real

xc ... any complex type
r ... same real type as xc
r=cr2len(xc)
Compute length of xc; xc is stored in cartesian format.
r=cr2phi(xc)
Compute phase of xc; xc is stored in cartesian format.
r=cget(xc,0)
Get real part or length of xc (depends on format of xc).
r=cget(xc,1)
Get imaginary part or phase of xc (depends on format of xc).

real->complex

x ... any real type
y ... same type as x
rc ... same complex type as x
rc=cset(x,y)
Combine elements of x (real part or length) and y (imaginary part or phase) to complex numbers.

multiplication (element-wise)

xc ... any complex type (re,im)
yc ... same complex type as 'xc'
n ... real or complex number (re,im)
result rc ... same complex type as xc
rc=cmul(xc,n)
rc=cmul(n,xc)
Multiply each element of xc with the real or complex number n.
rci,j = xci,j * n
rc=cmul(xc,yc)
Multiply xc and yc element by element.
rci,j = xci,j * yci,j

special functions

rcmatrix=ctrn(xcmatrix)
Transposed the complex matrix xc.
rci,j = xcj,i
rcscalar=cdot(xcvector,ycvector)
Compute the dot product (inner product) of the two complex vectors xc and yc (both with N elements).
rc = sumi=0..N-1 (xci * yci) , i=0..N-1
rcmatrix=cmulv(xcvector,ycvector)
Compute the tensor (or dyadic) product of the two complex vectors xc and yc.
rci,j = xci * ycj
rcvector=cmulv(xcvector,ycmatrix)
Compute the product of the complex vector xc (N elements) and the complex matrix yc (N rows, M columns).
rcj = sumi=0..N-1 (xci * yci,j) , j=0..M-1
rcvector=cmulv(xcmatrix,ycvector)
Compute the product of the complex matrix xc (N rows, M columns) and the complex vector yc (M elements).
rci = sumj=0..M-1 (xci,j * ycj) , i=0..N-1
rcmatrix=cmulv(xcmatrix,ycmatrix)
Compute the product of the complex NxM matrix xc and the complex MxL matrix yc. The result is the complex NxL matrix rc.
rci,k = sumj=0..M-1 (xci,j * ycj,i) , i=0..N-1 and k=0..L-1


See also
complex numbers, vvset, vvget, vv, fft, dft,

<function list>

Navigation menu

Personal tools