McIDAS-X User's Guide
Version 2024.1

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PTDISP

Displays point data.

Format

PTDISP dataset frame [keywords]

Parameters

dataset	ADDE dataset name and position; specify one of the following formats:
		group/descriptor.position alias.position
	a position greater than zero represents an absolute position in the dataset; a position less than or equal to zero represents a relative position in the dataset based on date and time, for example, 0 is the most recent and -1 is the next most recent; the position ALL represents all positions in the dataset (no default for group/descriptor or alias; position default=ALL if DAY is specified with the SELECT keyword, otherwise default=0)
frame	frame number to display the output; specify OPP to display the output on the frame opposite the current frame (default=current)

Keywords

PARam=	p1 . . pn list of parameters to plot; the list can contain native and/or computed parameters in the following formats:
		native_parameter[unit] native parameter and its output units; native parameters are those that are stored in the point file (no default for parameter; unit default=from dataset)
		'computed_parameter[unit]=expression' computed parameter, its output units, and the mathematical expression used to compute it; computed parameters do not exist in the point file but are derived with the specified mathematical expression containing math operators (+ - * etc.) and the native parameters specified in the Pn keywords, e.g., PAR=ID T[F] TD[F] 'TDD[F]=P1-P2' PSL[MB]; see the Remarks and the Pn keyword description for more information (no default for parameter or expression; unit default=from dataset)
SELect=	'clause1; clause2; . . ; clausen' finds only the data matching the values in the select clauses; single quotes are mandatory; separate select clauses with semicolons; specify clause as a range or a list using one of the following formats:
		range:	parameter[unit] bval eval
		list:	parameter[unit] val1,val2, . . ,valn
		parameter	point file parameter
		[unit]	units for the parameter values; units are optional but must be in square brackets if specified; see the Remarks (default=from dataset)
		bval eval	range of parameter values; see the Remarks
		val1,. .,valn	list of parameter values

Mathematical Operations Keyword

Pn=	parameter[unit] 'clause1; clause2; ..; clausen' native parameters to use in the math expressions specified in the PARAM keyword; use a number between 1 and 99 in the keyword name (P1,P2,..,P99); each keyword specifies a single native parameter and units to substitute in matching Pn values in the math expressions, where:
		parameter[unit] is the native parameter name and units; unit defaults to those for the parameter in the dataset; there is no default for parameter
		'clause1; clause2; ..; clausen' are the clauses used to select data for this keyword; only data matching their criteria is used; they are specified exactly as in the SELECT keyword; the Pn keywords inherit the clauses specified in the SELECT keyword, therefore, you should specify a Pn keyword clause only if a value differs from that in the SELECT keyword or you need to add additional clauses; for example, to set the values of P1 and P2 to the 850 and 1000 mb temperatures in degrees Celsius at 0 UTC, respectively, specify the following keywords: SEL='TIME 0; P 850' P1=T[C] P2=T[C] 'P 1000'

Navigation Keywords

LAT=	lat1 lat2	latitudes of the points at the lower-right and upper-left corners of the map; you cannot use LAT with the NAV or MAP keyword
LON=	lon1 lon2	longitudes of the points at the lower-right and upper-left corners of the map; you cannot use LON with the NAV or MAP keyword
MAP=	map for the plot; see the MAP command for a list of valid predefined maps, for example, MID, USA, WORL; you cannot use MAP with the NAV, LAT or LON keyword
MCOlor=	graphics color level of the map (default=1)
NAV=	num	frame to use for navigation
	C	use the current frame's navigation; the plot is drawn using the navigation of the specified frame; no map is drawn; you cannot use NAV with the MAP, LAT or LON keyword
PRO=	CONF	polar stereographic or Lambert conformal projection
	MERC	Mercator projection (default)
SLAt=	lat1 lat2	standard latitudes for a CONF projection; two values for a general Lambert conformal projection; one value for a polar stereographic projection (default=60 60 for northern hemisphere maps defined with the LAT and LON, or MAP keywords; -60 -60 for southern hemisphere maps defined with the LAT and LON, or MAP keywords)
SLOn=	standard longitude for a CONF projection (default=computed)

Plot Keywords

COLor=	c1 . . cn		graphics color level for each parameter specified with the PARAM keyword (default=3); each of the c1 . . cn values can be specified as a single number, e.g., COLOR=3 5 6, or in formatcolor[min-maxBinc] to assign multiple colors for the parameter, based on its values; see the Remarks for details
DEClut=	YES		declutters the plot; does not plot overlapping values (default)
	NO		does not declutter the plot
ELE=	bele eele		beginning and ending frame elements for output; specify MAX for maximum element number (default=1 MAX when using the NAV keyword; default=20 MAX-20 when using the MAP keyword)
FORMAT=	f1 . . fn		output format for each parameter specified with the PARAM keyword; valid formats are A, I, F, E, K, VECT, FLAG, SYMB, WXCM, WXCA, WPCM, and WPCA; see the Remarks (default=from dataset)
LINe=	blin elin		beginning and ending frame lines for output; specify MAX for maximum line number (default=1 MAX-57 when using the NAV keyword; default=20 MAX-57 when using the MAP keyword)
LOC=	symbol color size marks the location of each observation with a centered symbol in the specified graphics color level and size; valid symbols are +, ., , o and CLOUD*, where CLOUD plots the symbol for the maximum cloud cover in the CC1, CC2 and CIGC parameters in ISFC-schema point files (default=+ 3 6 if LOC keyword is specified; otherwise no symbol)
LSIze=	l1 . . ln		plotted height, in pixels, of each parameter specified with the PARAM keyword (default=8)
MULtiply=	m1 . . mn		multipliers for each parameter specified with the PARAM keyword; each parameter is multiplied by the specified number before plotting; use a number between 0 and 1 to divide (default=1)
OFFset=	l1 e1 . . ln en		frame line and element offset from the center plot position; useful when plotting multiple parameters; specify the offset for each parameter using minus (-) for up and left and plus (+) for down and right; the center of the text or symbol is plotted at the specified offset position (default=0 0)
TDAy=	CAL	displays the calendar day on the default title; not valid if the ELE, LINE or PAN keyword is used
	JUL	displays the Julian day on the default title (default)
TITLE=	'text' col line ele size text, color, location and size for the title
		'text'	72 characters maximum; specify X without quotes for the default title (default=computed)
		col	graphics color level of the title (default=value from the COLOR keyword)
		line	beginning TV line to write the title (default=lower-left corner of frame; exact line number depends on frame size and the value specified with the COLOR keyword)
		ele	beginning TV element to write the title (default=20)
		size	height of the title text in pixels (default=8)
WINd=	type par1 par2 wind type (speed and direction, or u and v components) and the corresponding parameter names in the point file; use this keyword only with PARAM=WIND; specify type, par1 and par2 as follows:
		type	SPDDIR if the two parameters define speed and direction, or UV if the two params define u and v
		par1, par2	corresponding parameter names in the point file
	(default=SPDDIR SPD DIR; if you specify WIND=UV, then the defaults for par1 and par2 are U and V)

Output Keyword

BYTecount=	YES	lists the number of bytes received from the server
	NO	does not list the number of bytes (default)

Remarks

PTDISP displays data from records in a point data file. The SELECT keyword defines which records to match and the PARAM keyword defines which parameters in the matching records to display. If PTDISP has started to plot data, you can stop it by pressing Alt Q.

If you use the range format for the SELECT keyword and bval is less than eval, all values between and including bval and eval are selected. For example, if you specify SELECT='LON -177 177', the longitude values -177, -176, . . , 176, 177 are selected. If bval is greater than eval, all values greater than bval or less than eval, including bval and eval, are selected. For example, if you specify SELECT='LON 177 -177', the longitude values 177, 178, 179, 180, -179, -178 and -177 are selected. This feature also allows you to select only wind directions from northwest to northeast with SELECT='DIR 315 45'.

You can assign output plot color based on the parameter's values by using the COLOR keyword format color[min-maxBinc], where color is the beginning graphics color level, min and max indicate the range of parameter values to color-code, and inc is the increment (the dash means "to" and the B means "by"). For example, when plotting integer values, COLOR=2[30-59B10] plots values 30-39 in level 2, values 40-49 in level 3, and values 50-59 in level 4. Values less than 30 are in level 1, and values greater than 59 are in level 5. When plotting floating point values (e.g., FORMAT=F5.2), COLOR=2[30-59.99B10] plots values 30.00-39.99 in level 2, values 40.00-49.99 in level 3, and values 50.00-59.99 in level 4. Values less than 30.00 are in level 1, and values greater than 59.99 are in level 5. Also, when plotting color-coded wind flags (PAR=WIND with FORMAT=FLAG), the units of the min and max values are knots, even if you specify PAR=WIND[MPS].

Use the FORMAT keyword options below to format output based on FORTRAN designators for data output:

Designator	Description
A	character
I	integer
F	floating point
E	exponential

To specify a parameter's output format, use a designator followed by a positive number. For example, I4 specifies an integer of up to four digits; A4 specifies up to four characters; I6.4 specifies an integer of up to six digits and will add leading zeros if necessary to get to four digits; F10.1 specifies a floating point decimal of up to 10 digits (including the decimal point) with one digit to the right of the decimal; E10.3 specifies an exponential number of up to 10 characters (including the decimal point and the four-character exponential flag) with three digits to the right of the decimal. Specify an X to use the parameter's default format. If the specified integer or floating point format is too small for the parameter's values, a series of asterisks (***) is plotted.

Use the K format to "clip" leading integer digits and drop the decimal portion of an integer or floating point value. Follow the K with a number to specify the number of integer digits to display. For example, if a pressure value is 1016.26 and you specify FORMAT=K3, 016 is plotted. If you also specify MULTIPLY=10, 163 is plotted.

Specify FORMAT=SYMB to translate weather report types (R-, S+, for example) into equivalent weather symbols. Only the first type in the report is plotted.

Specify FORMAT=WXCM, WXCA, WPCM or WPCA to translate WMO numeric codes into equivalent weather symbols. The table below shows the ISFC and SYN MD file schema parameter combinations that correspond to each format.

Format	Schema	Parameters (and values if required)
WXCM	ISFC SYN	WXC1, WXC2, WXC3 and WXC4 WXC1 with STYP=1, 2 or 3
WXCA	SYN	WXC1 with STYP=4, 5, 6 or 7
WPCM	SYN	WPC1 and WPC2 with STYP=1, 2 or 3
WPCA	SYN	WPC1 and WPC2 with STYP=4, 5, 6 or 7

If you specify FORMAT=VECT or FLAG, you must also specify PARAM=WIND, which requests wind speed (SPD) and direction (DIR) from the point file. The VECT format produces a wind vector display. The FLAG format produces a wind flag display. The vector or flag is placed at the center plot position; using the OFFSET keyword has no effect.

Wind flag symbols use triangular flags, and long and short lines, or barbs, to represent wind speed. For example, the wind flag shown here represents a wind speed of 75 knots or 37.5 meters/second.

a flag represents 50 knots or 25 meters/second
a long barb represents 10 knots or 5 meters/second
a short barb represents 5 knots or 2.5 meters/second.

A default title is constructed using the information specified with the PARAM and SELECT keywords. For example, if your command contains the keywords PARAM=T[F] TD[C] SELECT='DAY 96325; TIME 12; TYPE 0', the default title is: T[F] TD[C] DAY=96325 TIME=12 TYPE=0. Use the TITLE keyword if you want to choose a different title.

When using the SELECT and PARAM keywords, you can use the following units:

Unit type	UNIT=	Definition
Distance	CM	centimeters
	DM	decameters
	FT	feet
	GPM	geopotential meters
	IN	inches
	KM	kilometers
	M	meters
	MI	miles
	MM	millimeters
	NMI	nautical miles
	YD	yards
Pressure	HPA	hectopascals
	INHG	inches of mercury
	MB	millibars
Speed	KT or KTS	knots
	MPH	miles per hour
	MPS	meters per second
Temperature	C	Celsius
	F	Fahrenheit
	K	Kelvin

The PARAM keyword contains the parameters to plot. The list can contain native and/or computed parameters.

Native parameters are those stored in the point file. They are specified in the PARAM keyword list in the format parameter[unit], where parameter is the parameter name in the file, and [unit] is the output units, which are optional but must be in square brackets if specified.

Computed parameters do not exist in the point file but are derived with a mathematical expression. They are specified in the PARAM keyword list in the format 'parameter[unit]=expression', where parameter is the user-defined parameter name; [unit] is the label units, which are optional but must be in square brackets if specified; and expression is the mathematical expression consisting of math operators and one or more native parameters defined in the Pn keywords.

The table below lists the math operators valid in the computed parameter expression in the PARAM keyword.

Math Operator	Function
+	addition
–	subtraction
*	multiplication
/	division
**	power
SQRT	square root
EXP	exponential (the number e raised to a power)
LOG	natural logarithm
LOG10	base 10 logarithm
SIN	sine
COS	cosine
TAN	tangent
ASIN	arcsine
ACOS	arccosine
ATAN	arctangent
ABS	absolute value
MIN	minimum of two grids
MAX	maximum of two grids

To compute a power of ten, such as 102 or 10-3 in the math expression of a computed parameter in the PARAM keyword, specify it in either the 1epower or 10**(power) format. For example, both 1e-5 and 10**(-5) represent 10-5. You must include the parenthesis with 10**(-5) for it to be interpreted correctly.

The following character limits exist for the PARAM keyword:

256 characters maximum for the entire PARAM keyword list
12 characters maximum for the computed parameter name
12 characters maximum for the computed parameter units

When using point/MD files with CYD (ccyyddd) date units (e.g., FO14, IRAB, ISEN, ISFC, ISHP, PIRP and SYN schema MD files created with McIDAS-XCD 7.5 and later), commands PTCON, PTCOPY, PTDISP and PTLIST default to the current year if you don't specify a four-digit year and the nearest century if you specify only the last two digits of the year. For example, if the file uses CYD units for the DAY parameter and its value is 2004260, then you can specify the DAY in the SELECT keyword as 2004260 or 04260. If the current year is 2004, you can also specify it as 260. Use the PTLIST command with FORM=PARAM to list the file's parameters and units.

The PTCON, PTCOPY, PTDISP and PTLIST commands continue to work with point/MD files using the old SYD (ssyyddd) date units (e.g., FO14, IRAB, ISEN, ISFC, ISHP, PIRP and SYN schema MD files created with versions of McIDAS-XCD prior to 7.5), with the following exception: If you want to specify DAY in the SELECT keyword and the ss portion of the MD file's DAY value is nonzero, then you must specify the units with DAY in the SELECT keyword. For example, if the MD file uses SYD units for DAY and its value is 7197240, then it must appear as SELECT='DAY[SYD] 7197240'. If the MD file uses SYD units for DAY but has a zero (blank) ss value, you don't have to specify the units in the SELECT keyword. For example, if the MD file uses SYD units for DAY and its value is 97240 then it can appear as either SELECT='DAY 97240' or SELECT='DAY[SYD] 97240'.

If the dataset's schema has a key that represents time, such as HMS and TIME in the ISFC schema, it must be specified using the HH, HH:MM, or HH:MM:SS formats in the source dataset. For example, 12:00:00 UTC must be in the format 12, 12:00, or 12:00:00.

Examples

PTDISP SURFACE/ISFC SELECT='TIME 12' PARAM=T

This entry plots 12 UTC temperatures from the most recent point file in dataset SURFACE/ISFC. The temperatures are plotted using the navigation of the current frame and are in the units and format that the file uses for storing temperature.

PTDISP SURFACE/SYNOPTIC SELECT='TIME 18 ; DAY 96001' PARAM=T[C] FORMAT=I3 DECLUT=NO LAT=-40 -40 LON=-90 90 SLAT=-40 PRO=CONF TITLE='Antarctic Temperatures (deg C) at 18 UTC on 1 Jan 1996'

This entry plots 18 UTC temperatures in degrees Celsius from the point file storing the data for day 96001 in dataset SURFACE/SYNOPTIC. The temperatures are plotted as integers of up to three digits over a southern hemisphere map centered near the South Pole. All matching temperatures are plotted since DECLUT=NO is specified. The default title below the plot is replaced with the text Antarctic Temperatures (deg C) at 18 UTC on 1 Jan 1996.

PTDISP SURFACE/ISFC.5 OPP SELECT='TIME 12 ; T[F] 20 29' PARAM=T[F] FORMAT=I3 MAP=USA

This entry plots 12 UTC temperatures between 20 and 29 degrees Fahrenheit from the point file in position 5 of dataset SURFACE/ISFC. The temperatures are plotted on the frame opposite the current frame and are in degrees Fahrenheit over a map of the United States. The specified FORMAT keyword plots the temperatures as integers of up to three digits.

PTDISP SURFACE/ISFC.10 SELECT='TIME 17' PARAM=WIND T[F] TD[F] PSL[MB] ID FORMAT=FLAG I3 I3 K3 MULTIPLY=X X X 10 LSIZE=11 6 6 6 5 COLOR=7 5 4 3 2 OFFSET=0 0 -8 -13 3 -13 -8 3 3 3 MAP=MID TITLE='US Station Plot, 1700Z'

This entry displays a station plot of 17 UTC data from the point file in position 10 of dataset SURFACE/ISFC. The station plot includes wind flags, temperatures (in degrees Fahrenheit), dew point temperatures (in degrees Fahrenheit), altimeter settings (in millibars) and station IDs over a map of the Midwest. The LSIZE, COLOR and OFFSET keywords determine the plot size, graphics color level and offset from the center plot position of each of the five parameters. The altimeter settings are displayed in the standard meteorological format by using the K format to "clip" all but the last three integer digits after the observed values are multiplied by 10 with the MULTIPLY keyword. For example, an observed value of 1002.71 is displayed as 027; an observed value of 999.33 is displayed as 993.

PTDISP RAOB/MANDATORY.8 SELECT='LEV 850 ; TIME 0' PARAM=WIND T[C] TD[C] FORMAT=VECT I3 I3 LSIZE=12 7 7 COLOR=7 5 4 OFFSET=0 0 -12 2 4 2 MAP=OK PAN=1
PTDISP RAOB/MANDATORY.8 SELECT='LEV 500 ; TIME 0' PARAM=WIND T[C] TD[C] FORMAT=VECT I3 I3 LSIZE=12 7 7 COLOR=7 5 4 OFFSET=0 0 -12 2 4 2 MAP=OK PAN=2
PTDISP SURFACE/ISFC.8 SELECT='TIME 0' PARAM=WIND T[C] TD[C] FORMAT=VECT I3 I3 LSIZE=12 7 7 COLOR=7 5 4 OFFSET=0 0 -12 2 4 2 MAP=OK PAN=2 2 1

These entries create a three-panel display of 00 UTC wind vectors, temperatures and dew point temperatures from the point files in position 8 of datasets RAOB/MANDATORY and SURFACE/ISFC. The first entry displays the 850 millibar data in the upper-left quarter of the frame. The second entry displays the 500 millibar data in the upper-right quarter of the frame. The third entry displays the surface data in the bottom half of the frame. The FORMAT, LSIZE, COLOR and OFFSET keywords determine the format, plot size, graphics color level and offset from the center plot position of each of the three parameters.

PTDISP RTPTSRC/SFCHOURLY SEL='DAY #Y;TIME 18' PAR='DELP[MB]=P2-P1' P1=PSL[MB] P2=PSL[MB] 'TIME 21' FORMAT=F4.1 NAV=C

This entry plots today's 18 UTC to 21 UTC pressure change in millibars using the navigation of the current frame. The data is taken from the most recent point file in dataset RTPTSRC/SFCHOURLY.

PTDISP RTPTSRC/UPPERMAND SEL='DAY #Y;TIME 12' MAP=USA PARAM='THIK[M]=(287/9.8)*((P1+P2)/2)*LOG(1000/500)' P1=T[K] 'P 1000' P2=T[K] 'P 500'

This entry plots 1000-500 mb thickness in meters at 12 UTC today on a map of the United States. The thickness values are calculated using the equation in the PARAM keyword, known as the Hypsometric Equation.

PTDISP RTPTSRC/SFCHOURLY SEL='DAY #Y; TIME 20' MAP=USA PARAM=T[F] FORMAT=I4 COLOR=2[20-89B10]

This entry plots today's 20 UTC temperatures on a map of the United States. The temperatures are color coded: less than 20°F in graphics color level 1, 20-29°F in level 2, 30-39°F in level 3, 40-49°F in level 4, 50-59°F in level 5, 60-69°F in level 6, 70-79°F in level 7, 80-89°F in level 8, and 90°F and greater in level 9.

PTDISP RTPTSRC/SFCHOURLY SEL='DAY #Y; TIME 15' MAP=IL PARAM=WIND[KTS] FORMAT=FLAG COLOR=2[1-20B5]

This entry plots today's 15 UTC wind flags on a map of Illinois. The flags are color coded by speed: less than 1 knot in graphics color level 1, 1-5 knots in level 2, 6-10 knots in level 3, 11-15 knots in level 4, 16-20 knots in level 5, and greater than 20 knots in level 6. Note that each flag symbol may appear in two different colors because the speeds are rounded to the nearest five knot increment (i.e., 2.5-7.4 knot speeds are displayed as 5 knot flags, 7.5-12.4 knot speeds are displayed as 10 knot flags, 12.5-17.4 knot speeds are displayed as 15 knot flags, etc.). Thus, 5 knot flags can be in graphics color level 2 or 3, 10 knot flags can be in level 3 or 4, 15 knot flags can be in level 4 or 5, etc.

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