(File: \aacrse\505\acad\acad2id2.rtf)
You must know the DOS ‘cd’, ‘delete’, ‘copy
*.*’, ‘rename’ commands.
Create a subdirectory flyourinitials or delete
all the files in flyourinitials if this subdirectory has been used before
in some other exercise.
Copy all the files in the snowemp2 directory
to flyourinitials (COPY c:\snowemp2\*.* c:\flyourinitials). (The
files 200av3n.dat and 200bv3n.dat will be included in the transfer with
the snowemp2 database files.)
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(‘SNOWEMP2’ is similar to ‘SNOWEMP’ except
that a ‘Lithnum’ and a ‘Metals’ field have already been added to the LITH
Table, and a ‘Lithnum’ numerical code added as the last field in the input
file 200bv3n.dat . The fields in the STATI table have been reorganized
to allow output of a file containing GRIDX, GRIDY, and STATUM; ‘stati’,
‘litho’, ‘plot’, and ‘txt’ QUERY macros have been written into QUERY; and
the palette parameters (size, offset, etc) for the fields of interest in
the plotting procedure have also been modified .)
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1) Load Autocad and Fieldlog;
2) make a ‘flyourinitals’ map projection’
3) select it as the map projection to be used
in Map Project setup (make sure you select your USER PROJECTION ‘flyourinitials’,
otherwise Fieldlog will output the coordinates as UTM values).
4) Set your projection as the projection to
be used in ‘Points’ in the Tables setup for STATI;
5) import 200av3n.dat (GRIDX, GRIDY,
STATNUM, STATYPE, AND TRAVNUM) into the STATI Table, and 200bv3n.dat (STATNUM,
LITHCODE, ROCKTYPE, METALS, LITHNUM) into the LITHO Table. Check the tables
with ‘QUERY’.
Use QUERY to run the ‘txt’ query, and in the
PLOT menu click TEXT. Select ‘GRIDX’, ‘GRIDY’ (the coordinates of
the feature) and ‘STATNUM’ (the geographic definition feature Code),
in that order, as the fields to output as a VECTOR GEOGRAPHIC DEFINITION
file. Select ‘space’ as the Column (Field) Delimiter (that is, leave the
Field Delimiter box empty), click the projection box to select your projection,
and name the output file ‘c:\flyourintials\yourintialsxyz’ (NO EXTENSION;
Fieldlog will automatically add the ‘.txt’ extension, and NO ‘fl’ prefix
for the file name), and save it to your directory.
Repeat this procedure to output a file
composed of the fields ‘STATNUM’ (geographic definition feature code) and
‘LITHNUM’ (the numerical attribute value for the rock type). Name the file
‘c:\flyourinitials\yourinitialsstz’. (NO EXTENSION; Fieldlog will automatically
add the ‘.txt’ extension).
Use the Autocad ‘SHELL ENTER ENTER’ command
to get to DOS.
Change to your subdirectory, and check the
files with DOS EDIT (You MUST know the DOS ‘cd’, ‘edit filename’ and ‘rename’
commands).
Rename the file ‘yourinitialsstz.txt’
to ‘yourintialsstz.val’.
Type ‘Exit ENTER’ at the C: prompt to return
to Autocad.
Logoff , unload Fieldlog, and exit Autocad.
IDRISI
Load IDRISI and set the environment to your
directory ‘flyourinitials’. Run the module XYZIDRIS in ‘FILE-IMPORTS’ to
convert the ‘yourinitialsxyz.txt’ file to a ‘your initials.vec’ vector
file. Check the ‘yourinitials.dvc’ document file - click FILE on the menu
bar and then DOCUMENT. Click the ‘Vector’ button and double click the ‘File
to Document’ box. Double click the file in the ‘Pick File’ list, and if
necessary fill in the vector documentation file (Title - ‘yourinitials’,
ID type -Real, File type - Binary, Object type - Point, Reference system
- Plane, Reference units - Meters, Min X - 0 (12), Max X - 100 (80), Min
Y - 0 (19), Max Y - 100 (87), Unit distance - 1; the values in parenthesis
are the actual values calculated by Idrisi in the conversion of the xyz
file to the vec file).
Make a ‘your intitials.dvl’ document
file (e.g. wrc.dvl) for your ‘yourintialsstz.val’ values file. If Idrisi
says it can’t find a ‘yourinitialsstz.val’ document file, click OK, and
fill in the Document menu that will appear on the screen. Use ‘Ascii’ for
file type, ‘31’ for Records, ‘2’ for Fields, ‘Integer’ for Data type, ‘1’
for Minimum value, and ‘4’ for Maximum value. The Field 1 and Field 2 boxes
will be filled in automatically by IDRISI.
The vector file can now be displayed by selecting
Display Launcher in the DISPLAY menu, then clicking the ‘vector’ button,
double clicking the ‘Name of File to Display’ box to select your file (double
click the file name), and then the OK button. An image will be displayed
showing the stations as a set of red dots. (Check the ‘idrpnts’ standard
symbol palette. Then redisplay using the ‘qualitative 256’ point symbol
palette.) Note that the attribute attached to the points is the STATNUM
Geographic identifier, and serves only to relate the point’s location to
its attributes in the Attribute values files.
Next DISPLAY the vector file using the Attributes value
file with the ‘qual16’ palette. The points will now be displayed in a colour
corresponding to their rock type attribute value.
To convert a VECTOR image to an interpolated RASTER image
To generate an interpolated raster image, select
in sequence ‘DATA ENTRY’, ‘SURFACE INTERPOLATION’, and ‘INTERPOL’. Enter
the ‘Input Vector File’ name (e.g. ‘yourintials’; NO extension) and the
‘Output file name’ (e.g. ‘yourinitials’; NO extension). Enter a distance
weight exponent of 6. Click the ‘Use a values file for height’ box and
enter the name of the values .VAL file (e.g. ‘yourintials’; NO extension).
Enter ‘Columns’ as 512 and ‘Rows’ as 512, and ‘m’ for ‘Value units’. The
Min-Max values should be entered automatically. Examine the raster image
using the Display Launcher option in the DISPLAY menu, and selecting the
Idrisi256 pallette and Autoscaling. Note that since there are only four
attribute values, the colour for each value will correspond to multiples
of 64 in the Idrisi256 colour spectrum. Try using other palettes.
Generate an interpolated image as above, but
select the ‘Use Vector Point ID’s as heights’ option.
Try to understand the relational significance
of the vector geographic definition file and the complementary attribute
values file. What is an ‘attribute’?
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IDRISI provides no drawing tools that will
allow you to add objects to an existing vector image. It is possible however
to trace lines on a raster image onto a defined vector image using the
digitizing tool (red cross in a yellow filled circle). Read the IDRISI
help file on the subject of ‘Digitize’.
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