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A file on variable column ASCII format contains separators that separate one column from the next. A separator is usually some form white-space character(s), for example TAB.
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# Header: Variable columns sample file
101491.0 6760050. 2155.130
100162.0 6760540. 2217.300
98843.0 6761020. 2194.980
97514.0 6761500. 2229.990
96195.0 6761980. 2170.360
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A file on fixed column ASCII format uses column numbers to separate one column from the next. The sample file in Example 2 has Line name in columns 1 through 14.
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# Header: Fixed columns sample file
LINE-01 1640430.70S 431309.10E 996859.12854609.4
LINE-01 5640432.20S 431254.40E 996654.42854595.4
LINE-01 9640433.80S 431239.80E 996450.62854578.1
LINE-01 10640434.20S 431236.20E 996400.32854573.7
LINE-01 14640435.70S 431222.00E 996202.42854558.5
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In the example above, the columns used for X and Y are, 37-46, and 47-55 respectively.
ASCII menu
ASCII import menu
- Browse in the dataset. Geocap lets you browse in several datasets, enabling you to import them in one go, presuming they have the same formatting.
- Adjust the header spinbox so that header information is displayed in the header preview and the data is displayed in the data preview sections. Header preview will not be apart of the imported dataset.
- Set whether or not the file data columns are separated by white space or some other character. If your column separator is not on the list select Myseperator and type in the wished string. If your data is of type fixed width, tick the fixed columns box, and set the width of your specified columns. Read more about fixed column formats below.
- Geocap can read your data in X and Y's or in latitudes and longitudes. If your data is in latitudes and longitudes, you can choose between a variety of variants, e.g. decimal (deg) or DDMMSSSS.
- The Scalars field S can be used to read an "extra" data attribute. For instance when reading velocity data, Geocap recommends the user to read the velocities as the scalar field S. Geocap will expect the user to read X Y Z S where Z is the time value, and S is the velocity. Another example of the use of scalar is when reading interpretation data where the scalar can hold the amplitude.
- If your data has more fields than X, Y, Z and S, it is possible to add new fields. Add the extra attributes/fields as required. For each new file column defined, one needs to give the column a name, and also to specify whether the data input for this column is numeric or text.
- It is important that the user specifies which file column contains what data. In the example above, the following columns are defined: X-1, 2-Y, 3-Z, 4-SP, and 8-LineName(cell separator).
- Specify if your data is line, points or pointspoint cloud. The main difference is that line data will be displayed as lines, while points and points point cloud data will be displayed as points. In the example given above, interpretation data is read as lines to produce better display options (e.g. the interpretation along the 2D lines displayed as lines and not points).
- For both line and point data, it is possible to separate one dataset into separate cells. Sometimes this is necessary for display purposes, e.g. a coastline where each island along the coast has to be a separate cell (or else it would be impossible to display the data without connecting lines going from one island to the next). Another example of a dataset where cell separation is necessary, is velocity pairs, where all pairs from one analysis (SP) belong to one cell. In the example above, the cell separator is set to value change in column number 8 congaing the Seismic 2D line names, meaning that when displaying these data they will be displayed as lines (each cell one line).
- Geocap can also create many dataset from reading one single file. For instance, if you want to separate the interpretation data in the example dataset above into separate datasets, one for each seismic 2D line, then you would set Separate datasets to Value change and the Data separator column number to 8 which contains the Line Name. The new dataset will get the same name as the value of the Data separator, in this case the Line Name.
- It is also possible for Geocap to generate project folders based on input data. This option is always used in combination with the Separate dataset option. One example could be to import seismic velocities for many seismic vintages, where the year of acquisition was specified in one column. It would then be possible to set folder creation based on Year, Dataset creation based on Seismic survey, and cell separation based on SP change.
- Set the correct Schema for your dataset type. Seismic velocities would for instance be read under the schema Stacking Velocities.
Fixed column format
Often, the columns in data files are fixed, and the user needs to set the columns so that they read the correct data.
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- Tick the Fixed columns option.
- Use the combo box to select the column to set. This has to be done for each column to read. Notice that the characters of one sample line are displayed and the that selected columns set characters are displayed in red color.
- Use the arrows to move set character positions to read to the left or right.
- Use the small up and down arrows to set the total number of characters to read for the selected column.
ASCII import is used when:
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