Week of January 29

• Today’s agenda:– Announcements & reminders– Assignment #1 is due today– File encryption for peace-of-mind– Printing, the never-ending saga …– New MFworks operations– Assignment #3– Work session for Assignment #2 & #3

Announcements & Reminders

• Assignment #2 is due next week

• What to do if your Zip disk experiences “problems”– Do NOT initialize the disk– See Joe in 2215 to recover the information– If Joe is not around - slip the disk under his

door with a note explaining the problem and your name

If you haven’t done so already, Submit Assignment #1

Apple File Security

• You can use this to prevent others from looking at or using your work

• You can do this to files you are leaving on the hard-drive in the User-files (temp) folder

How to do it

• Open the “items for GISCI” folder on the desktop

• Double-click “Apple File Security”

• Select the name of the file you wish to encrypt

Fill in the passphrase dialog box

Be sure that“Add to Keychain” is NOT checked

Enter a passphraseSomething you will remember!Suggestion: your student #If you forget the passphrase then the file is toast!

The result…

• The file is secure from others

• Double-clicking the file will prompt you for the passphrase

• Secure files have a small “key” in their icon

Printing

• Latest news is …we can print!

• Printing will be to the GIS lab Black and White laser printer

• No need to change any options or settings when you do print

• Do not change the default printer

New MFworks operations this week

• Boolean operations: NOT, AND, OR

• Combine

• Cross

Boolean operations: NOTMaplayer 1Cell value

Output layerCell value

0 1 1 0

MFworks NOTnot_example = NOT ("input layer 1”) ;

NOT

Boolean operations: AND

0 0 0 0 1 0 1 0 0 1 1 1

Maplayer 1Cell value

Maplayer 2Cell value

Output layerCell value

and_example = "input layer 1" AND "input layer 2" ;

MFworks AND

AND

Boolean operations: ORMaplayer 1Cell value

Maplayer 2Cell value

Output layerCell value

0 0 0 0 1 1 1 0 1 1 1 1

MFworks ORor_example = "input layer 1" OR "input layer 2" ;

OR

Combine

• Generates a new map

• Works on n input maplayers

• Each zone in the new map identifies a unique combination of values from the input layers

MFworks Combine syntax“combine-example” = Combine "input layer

1" with "input layer 2” ;

Combine in action

Combine

Another Combine example• using combine to compare an old map of

forest cover with a new map of forest cover.

Forest Cover in 1945 Forest Cover in 1992

The Combine would identify the cells where there has been no additional forest growth, where forest has been lost, where forest has been gained, and where no change has occurred.

CombineForest 1992Forest 1945

Cross

• The Cross operation performs map layer cross tabulation

• It works like a Recode + Combine operation where you assign values to specific zones in the output map layer by combining values from the input map layers

MFworks Cross syntax"cross-example" = Cross "input layer 1" and "input layer

2" Assigning 0 To 0 With 0Assigning 1 To 1 With 0Assigning 2 To 0 With 1Assigning 3 To 1 With 1 ;

Cross in action

CrossAssigning:0 To 0 With 01 To 1 With 02 To 0 With 13 To 1 With 1

Another Cross exampleWith a map of a flood and a map of roads, you could identify places where roads were flooded.

Flood mapRoad map

Cross

Assignment #3

• Spatial Multicriteria Decision Making• Using a GIS to find a place to live

– What are some criteria to consider when choosing a residence?

• Data files for this assignment are found in two folders in the Geog280b folder on the OSX1B drive:

Assignment #3 is duethe week of Feb. 12

Remainder of today

• Work session on Assignments #2 and #3• Any questions?