Axis 282 Uživatelský manuál stáhnout pdf (Strana 55)

Chapter II-12 — Graphs

II-287

Yet another variation on labeling and units is provided by Exponent Prescale, which is found on the Ticks

and Grids tab of the Modify Axis dialog. Using Exponent Prescale you can force the tick and axis label

scaling to values different from what Igor would pick. For example, if you have data whose x scaling ranges

from, say, 9pA to 120pA and you display this on a log axis, Igor will label the tick marks with 10pA and

100pA. But if you really want the tick marks labeled 10 and 100 with pA in the axis label, you can set the

prescaleExp to 12. For details, see Axis Labels on page II-282.

To see this, use the following commands:

Make/O jack=x

Display jack

SetScale x,9e-12,120e-12,"A",jack // X scale 9 to 120 pico Amps

ModifyGraph log(bottom)=1

At this point we have a graph with a logarithmic bottom axis, and the major tick

labels are 10 and 100 pA (we show only the bottom axis).

You would like to force the “pA” into the axis label, so you set Exponent Pres-

cale to 12.

Exponent Prescale also works with normal axes (that is, not log). It may interact

confusingly with the high and low trip points. Exponent Prescale only applies when the range of the axis is

such that it does not trigger a trip point (note that the trip point is compared with the axis values after the

exponent prescale is applied).

Here are examples of the above axis in both log and normal modes, with several values of Exponent Pres-

cale. For these examples the low trip has been set to 1e-12 to avoid the confusing interactions, and the axis

label was “\U” to display units, if any. In the examples with units, the units are “A”.

Log Axis with Units Normal Axis with Units Log Axis, no Units Normal Axis, no Units

Prescale Exponent = 12

Prescale Exponent = 9

Prescale Exponent = 6

Prescale Exponent = 0

Fre

uenc

Log Axis range: 1E3..1E9 ; Wave units: none ; Axis label text: Frequency

1kHz 10kHz 100kHz 1MHz 10MHz 100MHz 1GHz

Fre

uenc

Log Axis range: 1E3..1E9 ; Wave units: Hz ; Axis label text: Frequency

0pA

2 3 4 5 6 7 8 9

100p

2 3 4 5 6 7 8 9

100

2 3 4 5 6 7 8 9

100

10080604020

2 3 4 5 6 7 8 9

100

x10

-12

10080604020

x10

-12

0.01

2 3 4 5 6 7 8 9

0.1

0.100.080.060.040.02

0.01

2 3 4 5 6 7 8 9

0.1

x10

-9

0.100.080.060.040.02

x10

-9

10µA

2 3 4 5 6 7 8 9

100µA

µA

0.000100.00005

µA

-5

2 3 4 5 6 7 8 9

-4

x10

-6

10080604020

x10

-12

10pA

2 3 4 5 6 7 8 9

100pA

10080604020

-11

2 3 4 5 6 7 8 9

-10

10080604020

x10

-12

1 2 ... 50 51 52 53 54 55 56 57 58 59 60 ... 79 80

Komentáře k této Příručce

Žádné komentáře

Axis 282 Uživatelský manuál Strana 55

Komentáře k této Příručce

Související produkty a manuály pro Sítě Axis 282