Axis 282 Bedienungsanleitung PDF herunterladen (Seite 46)

Chapter II-12 — Graphs

II-278

Dimension labels allow you (or Igor) to refer to a row or column of a wave using a name rather than a

number. Thus, the Tick Type column doesn't have to be the second column (that is, column 1). For instruc-

tions on showing dimension labels in a table, see Showing Dimension Labels on page II-191.

Date/Time Axes

In addition to numeric axes, Igor supports axes labeled with dates, times or dates and times.

Dates and date/times are represented in Igor as the number of seconds since midnight, January 1, 1904. There is

no practical limit to the range of dates that can be represented except on Windows where dates must be greater

than January 1, 1601. Prior to Igor Pro 6.1 Igor supported dates in the range 1904 to 2040 only.

In Igor, a date can not be accurately represented in a single precision wave. Make sure you use double precision

waves to store dates and date/times. (A single precision wave can provide dates and date/times calculated from

its X scaling, but not from its data values.)

Times without dates can be thought of in two ways: as time-of-day times and as elapsed times.

Time-of-day times are represented in Igor as the number of seconds since midnight.

Elapsed times are represented as a number of seconds in the range -9999:59:59 to +9999:59:59. For integral

numbers of seconds, this range of elapsed times can be precisely represented in a signed 32-bit integer

wave. A single-precision floating point wave can precisely represent integral-second elapsed times up to

about +/-4600 hours.

Igor displays dates or times on an axis if the appropriate units for the wave controlling the axis is “dat”.

This is case-sensitive — “Dat” won’t work. You can set the wave’s units using the Change Wave Scaling

item in the Data menu, or the SetScale operation.

To make a horizontal axis be a date or time axis for a waveform graph, you must set the X units of the wave

controlling the axis to “dat”. For an XY graph you must set the data units of the wave supplying the X coor-

dinates for the curve to “dat”. To make the vertical axis a date or time axis in either type of graph, you must

set the data units of the wave controlling the axis to “dat”. (If you’re not sure what a “waveform graph” is,

see Creating Graphs on page II-238. If you are mystified by “wave controlling the axis”, see Waves and

Axes on page II-240.)

Blank entries make

ticks with no labels.

Dimension label “Tick Type” has

keywords to set tick types

Use keyword “Subminor” for subminor

ticks such as Igor uses on log axes.

TickLabels[][0].d TickLabels[][1].d TickPositions

Tick Type

20 degrees Major

22.5

30 Major 15

50 Major 9

100 Major 4.5

400 Major 1.125

Minor 21.4286

Minor 20.4545

Minor 19.5652

Minor 18.75

Emphasized 18

Minor 17.3077

Minor 16.6667

Minor 16.0714

Minor 15.5172

1 2 ... 41 42 43 44 45 46 47 48 49 50 51 ... 79 80

Kommentare zu diesen Handbüchern

Keine Kommentare

Axis 282 Bedienungsanleitung Seite 46

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Vernetzung Axis 282