Lesson 5 - Data Structures

8/17/2019 Lesson 5 - Data Structures

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TOPICS

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Lesson 5

Creating and Leveraging Data Structures

A. Arrays

B. Common Array Functions

C. Polymorphism

D. Auto-Indexing

E. Clusters

F. Type Definitions


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A. Arrays

D and !D ArraysCreating an Array Control and Constant

Initiali"ing Arrays


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Arrays

An array#• Is a collection of data elements

that are of same type.

•

$as one or more dimensions.• Contains up to %!&'( elements

per dimension) memory

permitting.

• Accesses elements *y its index.

+ote# The first element is index ,.


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ID arrayOne row of 1!e"ements

1.2 3.2 8.2 8.0 4.8 5.1 6.0 1.0 2.5 1.7

0 1 2 3 4 5 6 7 8 9

#D array$ive!row %y seven!co"umn ta%"e of &5e"ements

0 1 2 3 4 5 6

01

2

3

4

Arrays ' 1D and #D ()am*"es

Inde)

num%ers


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+,y -se Arrays

se arrays hen you or/ ith a collection of similar data and

hen you perform repetiti0e computations.


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iewing Arrays on t,e $ront Pane"

The element selected in the index display alays refers to the

element shon in the upper-left corner of the element display.

First element

at index 1econdelement at

index !

The elements at

index , are not

shon *ecause

element is selectedin the index display.


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Creating an Array Contro"

For a ne array#. 1elect an Array control from the

Contro"s palette on the front panel.

!. Place a data o*2ect) such as a

numeric control) into the arrayshell.

&. Add a second dimension) if necessary) *y

resi"ing the index.

From a *loc/ diagram terminal or ire#3. 4ight-clic/ the o*2ect and select CreateContro"

or CreateIndicator.


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Creating an Array Constant

For a ne array#. 1elect Array Constant from the $unctions

palette on the *loc/ diagram.

!. Place a constant) such as a numeric)

into the array shell.&. Add a second dimension) if necessary) *y

resi"ing the index.

From a *loc/ diagram terminal or ire#

3. 4ight-clic/ and select CreateConstant.


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Initia"i2ing Arrays

• 5ou can initiali"e an array or lea0e it uninitiali"ed.• For initiali"ed arrays) you define the num*er of elements in

each dimension and the contents of each element.

•

ninitiali"ed arrays ha0e dimension *ut no elements.


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#D Arrays

• !D arrays#

6 1tore elements in a grid.

6 4e7uire a column index and a ro index to locate an element)

*oth of hich are "ero-*ased.• Create a multidimensional array on the front panel *y right-

clic/ing the index display and selecting Add Dimension

from the shortcut menu.

• 4esi"e the index display until you ha0e as many dimensions

as you ant.


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3. Common Array $unctions

Array 1i"eInitiali"e Array

Array 1u*set

Build ArrayIndex Array


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Common Array $unctions

• Array 1i"e

• Initiali"e Array

• Array 1u*set

• Build Array

• Index Array


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Array Si2e


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Initia"i2e Array


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Array Su%set


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3ui"d Array


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Inde) Array


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C. Po"ymor*,ism


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Po"ymor*,ism

Po"ymor*,ism ! T,e a%i"ity of Is and functions toautomatica""y ada*t to acce*t in*ut data ofdifferent data ty*es

Functions are polymorphic to 0arying degrees#

• +one) some) or all of their inputs can *e polymorphic.

• 1ome accept numeric or Boolean 0alues.

• 1ome accept numeric or strings.

•

1ome accept scalars) numeric arrays) or clusters ofnumerics.


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Arit,metic $unctions Are Po"ymor*,icCom%ination 4esu"t


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D. Auto!Inde)ing

se in For 8oops and 9hile 8oops9a0eform :raphs

Auto-Indexing ith a Conditional Terminal

Creating !D ArraysAuto-Indexing Input to a 8oop


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Auto!Inde)ing+ire %ecomes t,icer

+ire remains t,e same si2e

Auto!Inde)ing Disa%"ed

Auto!Inde)ing (na%"ed

On"y one va"ue 6"ast

iteration7 is *assed out of

t,e "oo*

1D Array

1 # & 8 5

• Allos For 8oops and 9hile8oops to accumulate arrays at

their *oundaries.

• Is the default *eha0ior for

For 8oops.• Is disa*led *y default for

9hile 8oops.

• Is ena*led;disa*led *y right-

clic/ing on a tunnel.• Produces arrays that are alays

e7ual in si"e to the num*er of

iterations of the loop.


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+aveform 9ra*,• Is a graphical display of data.

• Displays one or more plots of

e0enly sampled measurements.

• Is used to plot pre-generated

arrays of data.

• Can display plots ith any

num*er of data points.


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C,arts vs. 9ra*,s ' Sing"e!P"ot


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Auto!Inde)ing wit, a Conditiona" Tunne"

4ight-clic/ on a tunnel and select

Tunne" :odeConditiona".


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• Inner "oo* creates co"umn e"ements.

• Outer "oo* stacs co"umn e"ements into rows.

Creating #D Arrays

1D Array

1 # & 8 5

#D Array


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Auto!Inde)ing In*ut

If the iteration count terminal is ired and arrays of differentsi"es are ired to auto-indexed tunnels) the actual num*er of

iterations *ecomes the smallest of the choices.


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Auto!Inde)ing In*ut

se an auto-indexing input array to perform calculationson each element in an array.

• 9ire an array to an auto-indexing tunnel on a For 8oop.

•

5ou do not need to ire the count %+' terminal.6 The For 8oop executes

the num*er of times

e7ual to the

num*er ofelements in the array.

6 The 4un *utton is not *ro/en.


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9OAL

()ercise 5!1

Conce*t= :ani*u"ating Arrays


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DISC-SSIO?

()ercise 5!1

Conce*t= :ani*u"ating Arrays

• In the All Data Channel case) ho can you 0erify that the

to approaches yield the same results> – Polymorphic Add of array ? scalar

– Auto-indexed array elements added to scalar


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(. C"usters

4easons To se ClustersCluster 0s. Arrays

Creating a Cluster Control and Constant

@rdering Items and 4esi"ing ClustersDisassem*ling and


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C"usters

• Clusters group data elements of mixed types.• Clusters are similar to a record or a struct in text-*ased

programming languages.


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+,y -se C"usters

• eep data organi"ed.6 8ogically group related data 0alues together.

6 Impro0e diagram reada*ility *y eliminating ire clutter.

• 4educe the num*er of connector pane terminals.


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C"usters vs. Arrays• Clusters are a fixed si"e.

• Clusters can contain mixed

data types.

• Clusters can *e a control) an

indicator) or a constant.6 All elements ha0e to *e controls)

indicators) or constants.

• Arrays 0ary in si"e.

• Arrays contain only one data

type.

• Arrays can *e a control) an

indicator) or a constant.


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Create a C"uster Contro"

For a ne cluster#

. @n the front panel) select Cluster

from the Contro"s palette.

!. Place a data o*2ect into the

cluster shell.

&. Place additional data o*2ects)

if necessary) into the shell.

From *loc/ diagram terminal or ire#

3. 4ight-clic/ and select CreateContro" or CreateIndicator.


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Create a C"uster Constant

For a ne cluster#

. @n the *loc/ diagram) select Cluster

Constant from the $unctions palette.

!. Place a constant into the cluster shell.

&. Place additional data o*2ects) ifnecessary) into the cluster shell.

From *loc/ diagram terminal or ire#

3. 4ight-clic/ and select CreateConstant.


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C"uster Order

•. Cluster elements ha0e a logicalorder unrelated to their position

in the shell.

•. 5ou can 0ie and modify the

cluster order *y right-clic/ingthe cluster *order and

selecting 4eorder Contro"s

In C"uster.


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Autosi2ing C"usters

• Autosi"ing helps youarrange elements in

clusters.

• +I recommends the

folloing#

6 Arrange cluster elements

0ertically.

6 Arrange elements compactly.

6 Arranges elements in their

preferred order.


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Disassem%"ing a C"uster

• se the n*undle By +ame function hene0er possi*le.• se n*undle function hen some or all cluster elements

are unnamed.


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:odifying a C"uster

• se Bundle By +ame hene0er possi*le to access

elements in a cluster.

• se Bundle hen some or all cluster elements are

unnamed.

5ou must

ire the

in*ut

c"uster terminal.


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Creating a C"uster on t,e Diagram

• se the Bundle function to programmatically create acluster on a *loc/ diagram.

• If the elements that are *undled ha0e la*els) you can

access them using the n*undle By +ame function.

@therise use the n*undle function.


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C,arts vs. 9ra*,s ' :u"ti!*"ot and @ 9ra*,


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P"otting Data

se the Conte)t Be"* indo to determine ho to ire

multi-plot data to 9a0eform :raphs) Charts and 5 :raphs.


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(rror C"usters

• 8a*=IE9 uses error clusters to pass error information.

• An error cluster contains the folloing elements#

6 statusBoolean 0alue that reports True if an error occurs.

6 code&!-*it signed integer that identifies the error.

6 source1tring that identifies here the error occurred.


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9OAL

()ercise 5!#

Tem*erature +arnings ' C"usters

Create clusters) reorder clusters) and use the cluster functions

to assem*le and disassem*le elements.


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DISC-SSIO?

()ercise 5!#

Tem*erature +arnings ' C"usters

• 9hat ould happen if you reordered cluster elements>

• 9hat ould happen if you added a cluster element to

9eather Data @ut>


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$. Ty*e Definitions

Type Definitions and Custom Data Types

Creating and Identifying Type Definitions

Controls

1trict Type Definitions


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Ty*e Definitions 6Ty*e Def7

• A type definition is a master copy of a custom data type%control) indicator) or constant'.

6 A custom data type is sa0ed in a .ctl file.

6 Instances of a type def are lin/ed to the .ctl file.

• Instances can *e controls) indicators) or constants.

• 9hen the type def changes) instances automatically update.

6 Changes include data type changes) elements added)

elements remo0ed) and adding items to an enum.


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Creating Ty*e Definitions 6Ty*e Def7

. 4ight-clic/ a control) indicator or constant and select

:ae Ty*edef.

. 4ight-clic/ the o*2ect again and select O*en Ty*e Def.

!. Edit control) if needed.

&. 1a0e control as a .ctl file.


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Identifying Ty*e Definitions 6Ty*e Def7

• 8oo/ for a glyph mar/ing the upper left corner of terminals

and constants.

• $o0er cursor o0er glyph to 0ie tip strip.

• =ie Context $elp hile ho0ering cursor o0er terminal or

constant.


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Ot,er Contro" O*tions

5ou can sa0e a custom control as#• Control

• Type Definition

•

1trict Type Definition


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Contro"

• Instances are not lin/ed to a.ctl file.

• Each instance is an independent copy of the control.

• sed to create controls that *eha0e li/e existing controls *ut

loo/ different.


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Strict Ty*e Definition

• 1trict type definitions are similar to a type definition in that#

6 All instances lin/ to .ctl file.

6 9hen attri*utes or data types change) all instances update.

• Examples# Changing a /no* to a dial) a round 8ED to a s7uare

8ED) or a dou*le to an integer.• 1trict type definitions enforce e0ery aspect of a instance

except la*el) description) and default 0alue.

• se strict type definitions to ensure all front panel instances

ha0e the same appearance.

i


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9OAL

()ercise 5!&

+eat,er +arnings ' Ty*e Definition

Create and modify a type-defined cluster control. se the

type definition in a calling =I and a su*=I.

i


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DISC-SSIO?

()ercise 5!&

+eat,er +arnings ' Ty*e Definition

+o that the 9eather Data control is sa0ed as a typedefinition) ho many instances of the cluster ould need to *e

updated to add ind speed data>


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Summaryui2

. 5ou can create an array of arrays.a' True

*' False


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Summaryui2 Answer

. 5ou can create an array of arrays.a' True

%7 $a"se

ou cannot drag an array data ty*e into an array

s,e"". BoweverE you can create two!dimensiona"

arrays.


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Summaryui2

!. 9hat is the 0alue of the Iterations indicatorafter running this =I>


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Summaryui2 Answer

!. 9hat is the 0alue of the Iterations indicatorafter running this =I>

8


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Summaryui2

&. 9hich of the folloing custom control settings defines thedata type of all instances of a control *ut allos for

different colors and font styles>

a' Control

*' Type definition

c' 1trict type definition

d' Cluster control


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Summaryui2 Answer

&. 9hich of the folloing custom control settings defines thedata type of all instances of a control *ut allos for

different colors and font styles>

a' Control

%7 Ty*e definition

c' 1trict type definition

d' Cluster control


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Summaryui2

3. 5ou ha0e input data representing a circle# Position) 5 Position)and 4adius. In the future) you might need to modify your data to

include the color of the circle.

9hat data structure should you use to represent the circle in your

application>

a' Three separate controls for the to positions and the radius

*' A cluster containing all of the data

c' A custom control containing a cluster

d' A type definition containing a clustere' An array ith three elements 4

6@E7


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Summaryui2 Answer

3. 5ou ha0e input data representing a circle# Position) 5 Position)and 4adius. In the future) you might need to modify your data to

include the color of the circle.

9hat data structure should you use to represent the circle in your

application>

a' Three separate controls for the to positions and the radius

*' A cluster containing all of the data

c' A custom control containing a cluster

d7 A ty*e definition containing a c"ustere' An array ith three elements 4

6@E7

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Lesson 5 - Data Structures