all functions - g

gammp
```
gammp(a, x)
or gammp(a, x, q, lg)

return P(a,x) = int[0 to x]{ du * u^(a-1)*exp(-u) } / gamma(a)
optionally return Q(a,x) = 1-P(a,x) and ln(gamma(a))

Note that erf(x)=gammp(0.5,x^2) and erfc(x)=gammq(0.5,x^2)
Also P(chi2|nu)=gammp(0.5*nu,0.5*chi2)
and Q(chi2|nu)=gammq(0.5*nu,0.5*chi2)
are the probabilities that an observed chi-square be less than
or greater than (P or Q) chi2 when there are nu degrees of freedom
(terms in the chi-square sum).

Interpreted function, defined at i/gammp.i   line 14

```

gammq
```
gammq(a, x)
or gammq(a, x, p, lg)

return Q(a,x) = 1 - int[0 to x]{ du * u^(a-1)*exp(-u) } / gamma(a)
optionally return P(a,x) = 1-Q(a,x) and ln(gamma(a))

Note that erf(x)=gammp(0.5,x^2) and erfc(x)=gammq(0.5,x^2)
Also P(chi2|nu)=gammp(0.5*nu,0.5*chi2)
and Q(chi2|nu)=gammq(0.5*nu,0.5*chi2)
are the probabilities that an observed chi-square be less than
or greater than (P or Q) chi2 when there are nu degrees of freedom
(terms in the chi-square sum).

Interpreted function, defined at i/gammp.i   line 50

```

gauss_gate
```
gauss_gate(times)

gate function used by gaussian_gate.  Refer to the source code
to learn how to write your own gate function, making proper use
of drat_start and drat_stop options in addition to the input times.
Interpreted function, defined at i0/drat.i   line 797

```

gauss_int
```
gauss_int(t)

returns time integral of Gaussian specified in call to gaussian_gate.
Interpreted function, defined at i0/drat.i   line 822

```

gaussian_gate
```
gaussian_gate(t0, tsigma, max_trans)

sets the drat_gate for the snap function to be a Gaussian
centered at time T0, with sigma TSIGMA, and maximum transmission
fraction MAX_TRANS.
Interpreted function, defined at i0/drat.i   line 841

```

gcd
```
gcd(a,b)

returns the GCD (greatest common divisor) of A and B, which must
be one of the integer data types.  A and B may be conformable
arrays; the semantics of the gcd call are the same as any other
binary operation.  Uses Euclid's celebrated algorithm.
The absolute values of A and B are taken before the operation
commences; if either A or B is 0, the return value will be 0.
Interpreted function, defined at i/gcd.i   line 10

```

generays
```
generays

Interpreted function, defined at i/ylmdec.i   line 120

```

geocentric
```
geocentric

Interpreted function, defined at i/kepler.i   line 209

```

get3_centroid
```
get3_centroid(xyz, nxyz)
or get3_centroid(xyz)

return 3D centroids for polygons with vertices XYZ.  If NXYZ is
specified, XYZ should be 3-by-sum(nxyz), with NXYZ being the
list of numbers of vertices for each polygon (as for the plfp
function).  If NXYZ is not specified, XYZ should be a quadrilateral
mesh, 3-by-ni-by-nj (as for the plf function).  In the first case,
the return value is 3-by-numberof(NXYZ); in the second case, the
return value is 3-by-(ni-1)-by-(nj-1).
The centroids are constructed as the mean value of all vertices
of each polygon.
Interpreted function, defined at i/pl3d.i   line 480

```

get3_light
```
get3_light(xyz, nxyz)
or get3_light(xyz)

return 3D lighting for polygons with vertices XYZ.  If NXYZ is
specified, XYZ should be 3-by-sum(nxyz), with NXYZ being the
list of numbers of vertices for each polygon (as for the plfp
function).  If NXYZ is not specified, XYZ should be a quadrilateral
mesh, 3-by-ni-by-nj (as for the plf function).  In the first case,
the return value is numberof(NXYZ); in the second case, the
return value is (ni-1)-by-(nj-1).
The parameters of the lighting calculation are set by the
light3 function.
Interpreted function, defined at i/pl3d.i   line 363

```

get3_normal
```
get3_normal(xyz, nxyz)
or get3_normal(xyz)

return 3D normals for polygons with vertices XYZ.  If NXYZ is
specified, XYZ should be 3-by-sum(nxyz), with NXYZ being the
list of numbers of vertices for each polygon (as for the plfp
function).  If NXYZ is not specified, XYZ should be a quadrilateral
mesh, 3-by-ni-by-nj (as for the plf function).  In the first case,
the return value is 3-by-numberof(NXYZ); in the second case, the
return value is 3-by-(ni-1)-by-(nj-1).
The normals are constructed from the cross product of the lines
joining the midpoints of two edges which as nearly quarter the
polygon as possible (the medians for a quadrilateral).  No check
is made that these not be parallel; the returned "normal" is
[0,0,0] in that case.  Also, if the polygon vertices are not
coplanar, the "normal" has no precisely definable meaning.
Interpreted function, defined at i/pl3d.i   line 421

```

get3_xy
```
get3_xy, xyz, x, y
or get3_xy, xyz, x, y, z, 1

Given 3-by-anything coordinates XYZ, return X and Y in viewer's
coordinate system (set by rot3, mov3, orient3, etc.).  If the
fifth argument is present and non-zero, also return Z (for use
in sort3d or get3_light, for example).  If the camera position
has been set to a finite distance with setz3, the returned
coordinates will be tangents of angles for a perspective
drawing (and Z will be scaled by 1/zc).
Interpreted function, defined at i/pl3d.i   line 520

```

```

returns the byte addresses of the non-record and record variables
in the binary file FILE, and lists of the record addresses, file
indices, and filenames for file families with history records.
The order of these two address lists matches the
corresponding lists of names returned by get_vars.
*addr_lists(4)   list of file indices corresponding to
*addr_lists(5)   list of filenames in the family
Builtin function, documented at i0/std.i   line 3279

```

get_argv
```
get_argv()

returns string array containing the argv from the command line.
The -batch and batch_include.i arguments are removed (not returned).
Builtin function, documented at i0/std.i   line 2503

```

get_cwd
```
get_cwd()
or get_home()

returns the pathname of the current working directory or of your
home directory.
Builtin function, documented at i0/std.i   line 2487

```

get_env
```
get_env(environment_variable_name)

returns the environment variable (a string) associated with
ENVIRONMENT_VARIABLE_NAME (calls ANSI getenv routine).
Builtin function, documented at i0/std.i   line 2496

```

get_home
```
get_home

Builtin function, documented at i0/std.i   line 2487

```
SEE get_cwd

get_kaps
```
get_kaps

Interpreted function, defined at i0/drat.i   line 1041

```

get_member
```
get_member(f_or_s, member_name)

returns F_OR_S member MEMBER_NAME, like F_OR_S.MEMBER_NAME syntax,
but MEMBER_NAME can be a computed string.  The F_OR_S may be a
binary file or a structure instance.
Builtin function, documented at i0/std.i   line 2641

```

get_mesh
```
get_mesh

Interpreted function, defined at i/demo4.i   line 66

```

get_ncycs
```
get_ncycs

Builtin function, documented at i0/std.i   line 3304

```
SEE get_times

get_path
```
get_path()

returns the current include file search path.
Builtin function, documented at i0/std.i   line 242

```

get_pkgnames
```
get_pkgnames(all)

returns list of package names, ALL non-zero means to return both
statically and dynamically loaded packages, otherwise just the
Builtin function, documented at i0/std.i   line 248

```

get_primitives
```
prims = get_primitives(file)

Return the primitive data types for FILE as an array of 32
integers.  The format is described under set_primitives.
Builtin function, documented at i0/std.i   line 2969

```

get_ray_path
```
ray_info= get_ray_path(path, rt, zt)

where PATH is one element of an array returned by track_rays,
returns the points where the ray cut the edges of the mesh (ZT, RT).
The returned RAY_INFO has two components: RAY_INFO(,1) is the z
coordinates and RAY_INFO(,2) is the r coordinates.
Interpreted function, defined at i0/drat.i   line 1255

```

get_s0
```
get_s0(rays)

returns the s-coordinate of the point of closest approach of
the RAYS to the origin x=y=z=0.  The length of the first dimension
of RAYS may be either 3, 5, or 6; this first dimension will not
be present in the result.
The s-coordinate represents distance along the ray, increasing in
the direction the ray moves.  The 5 and 6 component ray coordinates
include a reference point (x,y,z) on the ray; s=0 at that point.
For the 3 component ray coordinate, get_s0 always returns 0.
Interpreted function, defined at i/rays.i   line 223

```

get_std_limits
```
get_std_limits(rays, slimits)

returns slimits suitable for internal routines: 2-by-nrays,
with s=0 at point of closest approach to origin
Interpreted function, defined at i0/drat.i   line 913

```

get_style
```
get_style, landscape, systems, legends, clegends

get the detailed style of the current drawing.  The arguments
are all outputs:
landscape: 1 if drawing is landscape orientation, 0 if portrait
system:    an array of GfakeSystem struct instances, one per
coordinate system in this drawing (ordinarily just one).
legends:   a GeLegendBox structure instance describing the layout
of the plot legends
clegends:  a GeLegendBox structure instance describing the layout
of the contour legends
See the help for the GeLegendBox and GpTextAttribs structs for
the details of the legends and clegends arguments.  Basically,
you can adjust the location of the legends on the page, the
font and height of the characters used to render legends, and
whether the legends are split into two columns.
The coordinate systems are the systems accessible via the
plsys command.  The index of the system in the system array is
the index you use to switch to it in the plsys command.  Simple
styles have only one coordinate system, and you should carefully
consider whether you should design a graphic style with multiple
coordinate systems -- most likely, you can do a better job by
combining several separate Yorick pictures with some sort of
page layout program, rather than trying to do this work within
Yorick itself.
See the help for the GfakeSystem struct for complete details of
what you can adjust.  The most interesting features you can
control are the location and aspect ratio of the viewport, and
the details of the axis ticks and labels.  The gridxy function
provides a simpler interface for fiddling with ticks and labels
if that is all you need.  The system.viewport member is the
[xmin,xmax,ymin,ymax] of the rectangle on the page where your
plots will appear, expressed in NDC coordinates (0.0013 NDC units
equals one point, and there are 72.27 points per inch, and 2.54
cm per inch; the NDC origin is always at the lower left hand
corner of the paper, with x increasing leftward and y increasing
upward).  If you change the size of the viewport, you will also
need to change the parameters of the tick-generating model; like
other problems in typography and page layout, this is harder
than you might think.
Interpreted function, defined at i/style.i   line 10

```

get_times
```
times= get_times(file)
ncycs= get_ncycs(file)

returns the list of time or ncyc values associated with the records
if FILE, or nil if there are none.  The time values are not guaranteed
to be precise (but they should be good to at least 6 digits or so);
the precise time associated with each record may be stored as a record
variable.
Builtin function, documented at i0/std.i   line 3304

```

get_vars
```
name_lists= get_vars(file)

returns the lists of non-record and record variable names in the
binary FILE.  The return value is an array of two pointers to
arrays of type string; *name_lists(1) is the array of non-record
variable names (or nil if there are none), *name_lists(2) is the
array of record variable names.
The get_addrs function returns corresponding lists of disk
addresses; the get_member function can be used in conjunction
with the dimsof, structof, and typeof functions to determine
the other properties of a variable.
Builtin function, documented at i0/std.i   line 3252

```

get_ylm
```
get_ylm(pts, lmax, list)

returns values of Ylm at the 3-by-anything array of unit vectors
PTS, for all l and m up to LMAX.  The return value is
(lmax+1)*(lmax+2)/2-by-anything.  The LIST is also returned; its
value is [1, 2,2, 3,3,3, 4,4,4,4, ..., LMAX+1,LMAX+1,...,LMAX+1]
-- i copies of each integer i up to LMAX+1.  This can be useful
in conjunction with the histogram function; its values are l+1
for each element of the returned array's first index.  The m
values are [0, 0,1, 0,1,2, 0,1,2,3, 0,1,2,3,4, ...].  Negative m
values are omitted, since they would be the conjugates of m>0.
llist= list-1;
mlist= (!list(dif))(cum)-(list-2)*(list-1)/2;
Interpreted function, defined at i/ylmdec.i   line 34

```

getc3
```
getc3(i, m3, chunk)
or getc3(i, m3, clist, l, u, fsl, fsu, cells)

return cell values of the Ith function attached to 3D mesh M3
for cells in the specified CHUNK.  The CHUNK may be a list of
cell indices, in which case getc3 returns a (dimsof(CHUNK))
list of vertex coordinates.  CHUNK may also be a mesh-specific data
structure used in the slice3 routine, in which case getc3 may
return a (ni)x(nj)x(nk) array of vertex values.  There is no
savings in the amount of data for such a CHUNK, but the gather
operation is cheaper than a general list of cell indices.
Use getc3 when writing colorng functions for slice3.
If CHUNK is a CLIST, the additional arguments L, U, FSL, and FSU
are vertex index lists which override the CLIST if the Ith attached
function is defined on mesh vertices.  L and U are index lists into
the 2x2x2x(dimsof(CLIST)) vertex value array, say vva, and FSL
and FSU are corresponding interpolation coefficients; the zone
centered value is computed as a weighted average of involving these
coefficients.  The CELLS argument is required by histogram to do
the averaging.  See the source code for details.
By default, this conversion (if necessary) is done by averaging
the eight vertex-centered values.
Interpreted function, defined at i/slice3.i   line 725

```

getc3_rect
```
getc3_rect

Interpreted function, defined at i/slice3.i   line 756

```

getdate
```
getdate -- get date of the day in the form "DD/MM/YY"

SYNOPSIS: date= getdate();
getdate, date;

HISTORY: October 30, 1995 by Eric THIEBAUT.

Interpreted function, defined at i/string.i   line 35

```

gettime
```
gettime -- get current time in the form "HH:MM:SS"

SYNOPSIS: time= gettime();
gettime, time;

HISTORY: October 30, 1995 by Eric THIEBAUT.

Interpreted function, defined at i/string.i   line 23

```

getv3
```
getv3(i, m3, chunk)

return vertex values of the Ith function attached to 3D mesh M3
for cells in the specified CHUNK.  The CHUNK may be a list of
cell indices, in which case getv3 returns a 2x2x2x(dimsof(CHUNK))
list of vertex coordinates.  CHUNK may also be a mesh-specific data
structure used in the slice3 routine, in which case getv3 may
return a (ni)x(nj)x(nk) array of vertex values.  For meshes which
are logically rectangular or consist of several rectangular
patches, this is up to 8 times less data, with a concomitant
performance advantage.  Use getv3 when writing slicing functions
for slice3.
Interpreted function, defined at i/slice3.i   line 688

```

getv3_rect
```
getv3_rect

Interpreted function, defined at i/slice3.i   line 708

```

gnomon
```
gnomon
or gnomon, onoff

Toggle the gnomon display.  If ONOFF is non-nil and non-zero,
turn on the gnomon.  If ONOFF is zero, turn off the gnomon.
The gnomon shows the X, Y, and Z axis directions in the
object coordinate system.  The directions are labeled.
The gnomon is always infinitely far behind the object
(away from the camera).
There is a mirror-through-the-screen-plane ambiguity in the
display which is resolved in two ways: (1) The (X,Y,Z)
coordinate system is right-handed, and (2) If the tip of an
axis projects into the screen, it's label is drawn in opposite
polarity to the other text on the screen.
Interpreted function, defined at i/pl3d.i   line 734

```

gridxy
```
gridxy, flag
or gridxy, xflag, yflag

Turns on or off grid lines according to FLAG.  In the first form, both
the x and y axes are affected.  In the second form, XFLAG and YFLAG
may differ to have different grid options for the two axes.  In either
case, a FLAG value of 0 means no grid lines (the default), a value of
1 means grid lines at all major ticks (the level of ticks which get
grid lines can be set in the style sheet), and a FLAG value of 2 means
that the coordinate origin only will get a grid line.  In styles with
multiple coordinate systems, only the current coordinate system is
affected.
The keywords can be used to affect the style of the grid lines.
You can also turn the ticks off entirely.  (You might want to do this
to plot your own custom set of tick marks when the automatic tick
generating machinery will never give the ticks you want.  For example
a latitude axis in degrees might reasonably be labeled "0, 30, 60,
90", but the automatic machinery considers 3 an "ugly" number - only
1, 2, and 5 are "pretty" - and cannot make the required scale.  In
this case, you can turn off the automatic ticks and labels, and use
plsys, pldj, and plt to generate your own.)
To fiddle with the tick flags in this general manner, set the
0x200 bit of FLAG (or XFLAG or YFLAG), and "or-in" the 0x1ff bits
however you wish.  The meaning of the various flags is described
in the file Y_SITE/gist/work.gs.  Additionally, you can use the
0x400 bit to turn on or off the frame drawn around the viewport.
Here are some examples:
gridxy,0x233        work.gs default setting
gridxy,,0x200       like work.gs, but no y-axis ticks or labels
gridxy,,0x231       like work.gs, but no y-axis ticks on right
gridxy,0x62b        boxed.gs default setting
The three keywords base60=, degrees=, and hhmm= can be used to get
alternative tick intervals for base 60 systems instead of the
usual base 10 systems.  The keyword values are 0 to restore the
default behavior, 1 to set the feature for the x axis, 2 to set it
for the y axis, and 3 to set it for both axes.  The base60 feature
allows ticks and labels at multiples of 30 (up to +-3600).  The
degrees feature causes labels to be printed modulo 360 (so that a
scale which runs from, say, 90 to 270 will be printed as 90 to 180
then -180 to -90, mostly for longitude scales).  The hhmm feature
causes labels to be printed in the form hh:mm (so that, for example,
150 will be printed as 02:30, mostly for time of day scales).
KEYWORDS: color, type, width, base60, degrees, hhmm
Builtin function, documented at i0/graph.i   line 857

```

grow
```
grow, x, xnext1, xnext2, ...
or grow(x, xnext1, xnext2, ...)
or    _(x, xnext1, xnext2, ...)

lengthens the array X by appending XNEXT1, XNEXT2, etc. to its
final dimension.  If X is nil, X is first redefined to the first
non-nil XNEXT, and the remainder of the XNEXT list is processed
normally.  Each XNEXT is considered to have the same number of
dimensions as X, by appending unit-length dimensions if necessary.
All but this final dimension of each XNEXT must be right-conformable
(that is, conformable in the sense of the right hand side of an
assignment statement) with all but the final dimension of X.
The result has a final dimension which is the sum of the final
dimension of X and all the final dimensions of the XNEXT.  Nil
XNEXT are ignored.  The value of the result is obtained by
concatenating all the XNEXT to X, after any required broadcasts.
If invoked as a function, grow returns the new value of X; in
this case, X may be an expression.  X must be a simple variable
reference for the subroutine form of grow; otherwise there is
nowhere to return the result.  The subroutine form is slightly
more efficient than the function form for the common usage:
x= grow(x, xnext1, xnext2)           is the same as
grow, x, xnext1, xnext2              the preferred form
The _ function is a synonym for grow, for people who want this
operator to look like punctuation in their source code, on analogy
with the array building operator [a, b, c, ...].
The _cat function is sometimes more appropriate than grow.
Usage note:
Never do this:
while (more_data) grow, result, datum;
The time to complete this loop scales as the SQUARE of the number
for (i=1,result=array(things,n_init) ; more_data ; i++) {
if (i>numberof(result)) grow, result, result;
result(i) = datum;
}
result = result(1:i-1);
The time to complete this loop scales as n*log(n), because the
grow operation doubles the length of the result each time.
Builtin function, documented at i0/std.i   line 1036

```

guess_symmetry
```
guess_symmetry, f
or guess_symmetry(f)

guesses the symmetry of the problem in the dump file F based on
the variables f.isymz, f.rt, and f.zt.
If called as a subroutine, prints one of:
"no symmetry", "z=0 reflection symmetry", or "spherical symmetry"
If called as a function, returns 0, 1, or 2, respectively.
Interpreted function, defined at i0/drat.i   line 931

```