Merging gravity datasets (T56)
Contents
1. Back gt INTREPID User Manual Merging gravity datasets T56 4 Library Help Top lt 4 Back gt Gravity Merge Key group by field The key group by field is the field that links the datasets for the merge operation The datasets must each have a group by field with the name you specify INTREPID combines the datasets so that data from the input dataset is included in the matching groups in the output dataset The most common purpose for this tool is combining gravity datasets for the same region The normal gravity dataset group by field is the station number Gravity Merge can combine the datasets so that all of the data for a station is in the same group We recommend that you do not use Gravity Merge with a dataset which has the same group by field value for two or more groups e g if you have used the Split Group operation in the Spreadsheet Editor Edit such a dataset using the Spreadsheet Editor before merging to ensure that all groups have unique merge key values in each dataset To specify the key group by field Choose Specify Key Field from the File menu and select the field from the input dataset Detecting duplicates and updating During the merge process INTREPID examines the X Y and merge key usually station number fields and identifies suspected duplicate data points These four fields make the default fields to compare list If you use a task specification file you can2. For full instructions on creating and editing task specification files see INTREPID task specification job files R06 To use a task specification file in an interactive Gravity Merge session Load the task specification job file File menu Load Options modify any settings as required then choose Apply To use a task specification file for a batch mode Gravity Merge task Type the command merge exe with the switch batch followed by the name and path if necessary of the task specification file For example if you had a task specification file called surv329 job in the current directory you would use the command merge exe batch surv329 job Library Help Top 2012 Intrepid Geophysics lt 4 Back gt INTREPID User Manual Merging gravity datasets T56 8 Library Help Top 4 Back gt Task specification file notes and example Library Help Top Here is an example of a Gravity Merge task specification file Process Begin Name merge Input d survey suppdata Key station_number MergeWith d survey maindata ReportOn Elevation MergeLastOnly NO TimeStamp YES StopAfter 100 Process End Notes Input refers to the input dataset MergeWith refers to the output dataset You can specify additions to the fields to compare list using the ReportOn fieldname fieldname statement See Detecting duplicates and updating for further information You can in
3. add fields to this list using the ReportOn statement See Specifying further fields to compare Specifying further fields to compare If you are using a task specification job file for the Gravity Merge task you can specify additions to the fields to compare list using the ReportOn statement ReportOn fieldname fieldname Example ReportOn Elevation Deleting duplicates If the values for the fields to compare list are the same INTREPID regards the data point as a duplicate and ignores the record in the input dataset Reporting suspected errors If X and Y are the same but the merge keys are different or the merge keys are the same but X and Y are different INTREPID retains both data points and reports them as suspected duplicates or errors If the difference between the X and Y is only a question of precision number of significant figures and two records are in fact duplicates you will be able to note this from the report You can use the Spreadsheet tool to manually delete the data point that you don t require The number_samples function can show you the number of data points in each group See INTREPID Functions in INTREPID expressions and functions R12 Library Help Top 2012 Intrepid Geophysics 4 Back gt INTREPID User Manual Merging gravity datasets T56 5 Library Help Top Updating with Merging only 4 Back gt more complete data If the values for the fields to comp
4. are using a task specification file you can turn date stamping off or on Set the TimeStamp statement to YES or NO according to your requirements See Using task specification files for details Apply When you choose Apply INTREPID will carry out the merge process that you have specified Processing a specified number of data points If you are using a task specification job file you can limit the number of records that INTREPID reads from the input dataset This may save time when you are trialing a process To specify the maximum number of input dataset records to process Use the StopAfter statement in the task specification file Example StopAfter 1000 Exit To exit from the Gravity Merge tool choose Quit from the File menu Library Help Top 2012 Intrepid Geophysics 4 Back gt INTREPID User Manual Merging gravity datasets T56 7 Library Help Top lt 4 Back gt Using task specification files You can store sets of file specifications and parameter settings for Gravity Merge in task specification job files To create a task specification file with the Gravity Merge tool 1 Specify all files and parameters 2 If possible execute the task choose Apply to ensure that it will work 3 Choose Save Options from the File menu Specify a task specification file INTREPID will add the extension job INTREPID will create the file with the settings current at the time of the Save Options operation
5. INTREPID User Manual Library Help Top Merging gravity datasets T56 The INTREPID Gravity Merge tool can combine two vector datasets so that data points from matching groups are stored in the same group in the output dataset Group 1 Merging gravity datasets T56 1 lt 4 Back gt Top Gravity Merge is intended for combining gravity datasets where the data is grouped by station number You can merge two datasets so that INTREPID stores the data from each station in the same group For general purpose merging use the Merge Datasets tool see Merging datasets T04 Generally speaking both the input and output dataset must have the same fields and field names for the Gravity Merge process to work Gravity Merge will report Eliminated duplicates e Nulls Duplicate locations with different group by usually station number field values Duplicate group by usually station number field values with the same location field values Here is a diagram of the merge process Input dataset Deri R Do D ye _ Db D STEE R Merge process Pre existing output dataset Append ff 1 Group gt iY 2 ee E a Update _ Append o O 3 g 4 Append R Suspected error reported U Updated data point D Duplicate ignored or used for update INTREPID appends data points from the input dataset to any existing data in the output dataset If a point in the input da
6. are list are the same but there are some nulls INTREPID uses the data point with fewer nulls and ignores the other If the data point with fewer nulls is in the input dataset then we can say that the output dataset data point is updated the last data point in each group You can instruct INTREPID to merge only the last data point in each group of the input dataset This is a normal practice in the context of gravity dataset processing This option is only available if you are using a task specification job file To merge only the last record in each input dataset group Set the MergeLastOnly statement in the task specification file to YES See Using task specification files for details Gravity Merge process algorithm For each data Compare it If key field the same Then Else Here is a structured English statement of the algorithm used by the Gravity Merge tool for the merging process point in the input dataset with each data point in the output dataset values are the same and values in the fields to compare list are the input data point is a duplicate Ignore it or use it for update the input data point is not a duplicate Append it to the output dataset Gravity Merge reports and records Gravity Merge Library Help Top reports INTREPID prepares a report of the merge process which includes statistics on Duplicate data points found e Nulls found Differences in merge key field values f
7. ify the dataset that you wish to include in the output dataset using Gravity Merge Use Specify Input from the File menu See Specifying input and output files for detailed instructions 4 Specify the dataset into which you wish to insert the input dataset using Gravity Merge Use Specify Output from the File menu See Specifying input and output files for detailed instructions 5 Specify the Key group by field using the corresponding option from the File menu See Gravity Merge Key group by field for details 6 When you have made specifications and settings according to your requirements choose Apply INTREPID will perform the Gravity Merge process and save output dataset 7 Ifyou wish to record the specifications for this process in a task specification job file in order to repeat a similar task later or for some other reason use Save Options from the File menu See Specifying input and output files for detailed instructions 8 If you wish to repeat the process go to step 2 9 To exit from Gravity Merge choose Quit from the File menu This tool has a number of options available only if you use a task specification job file The headings describing these options have parentheses for example Turning date stamping on or off A summary of the features appears in Notes in Task specification file notes and example below You can execute Gravity Merge as a batch task using a task specification job file tha
8. more information about aliases Specify Input Use this option to specify the input dataset that you wish to include in the output dataset This dataset should contain the second part of the data to be combined Specify Key Field Use this option to specify the name of the group by for linking the data in the merge process Both datasets require the linking group by field to have this name See Gravity Merge Key group by field for details Specify Output Use this option to specify the output dataset into which you wish to insert the input dataset This dataset may contain the first part of the data to be combined or can be a new dataset After the process it will contain all of the data If you specify an existing output dataset INTREPID will build two internal hash tables to index the existing key and location fields Load Options If you wish to use an existing task specification file to specify the Gravity Merge process use this option to specify the task specification file required INTREPID will load the file and use its contents to set all of the parameters for the Gravity Merge process See Using task specification files for more information Save Options If you wish to save the current Gravity Merge file specifications and parameter settings as an task specification file use this option to specify the filename and save the file See Using task specification files for more information 2012 Intrepid Geophysics 4
9. or the same location and Differences in locations for the same merge key field values See Diagnostic reporting options in Configuring and using INTREPID R04 for information about process reporting in INTREPID 2012 Intrepid Geophysics 4 Back gt INTREPID User Manual Merging gravity datasets T56 6 Library Help Top lt 4 Back gt Algorithm for reporting the merge process Here is a structured English statement of the algorithm used by the Gravity Merge tool for reporting the process For each data point in the input dataset Compare it with each data point in the output dataset If key field values are the same Then If all fields to compare list values are the same then it is a duplicate Report data point ignored If X or Y field values are not the same then there are two different locations with the same key usually station number Report duplicate key Else If X and Y field values match then there are two key values usually station numbers for the same location Report duplicate location If any fields to compare list values are null Then Report null fields Date stamping merged data points INTREPID can date stamp data points as they are merged to the output dataset If the field HISTORYDate exists in the output dataset INTREPID will set it to the current date using a yyyy mm dad string in each data point that it appends or updates Turning date stamping on or off If you
10. struct INTREPID to merge only the last data point in each group of the input dataset using the MergeLastOnly YES NO statement This is a normal practice in the context of gravity dataset processing See Merging only the last data point in each group for details You can turn date stamping off or on using the TimeStamp YES NO statement See Date stamping merged data points for further details You can limit the number of records that INTREPID reads from the input dataset using the StopAfter number_of_data_points statement This may save time when you are trialing a process 2012 Intrepid Geophysics lt 4 Back gt
11. t you have previously prepared See Using task specification files for details Library Help Top 2012 Intrepid Geophysics 4 Back gt INTREPID User Manual Merging gravity datasets T56 3 Library Help Top 4 Back gt Specifying input and output files Library Help Top To use Gravity Merge you will need to specify the two vector datasets to be combined and the key field Choose the options as required from the File menu In each case INTREPID displays an Open or Save As dialog box Use the directory and file selector to locate the file you require See Specifying input and output files in Introduction to INTREPID R02 for information about specifying files Vector dataset notes INTREPID will identify X and Y fields from the dataset aliases for the process The dataset must have the following aliases identifying appropriate fields Alias Field X X coordinate location Y Y coordinate location Ifyou wish to identify duplicate locations with the same group by field usually station number we recommend that you use geographical coordinates latitude longitude If you do not have a set of latitudes and longitudes available for assigning to aliases you can create them using the Projection Conversion tool See INTREPID s supported datums and projections R09 for instructions See Vector dataset field aliases in INTREPID database file and data structures R05 for
12. taset has fewer nulls than a duplicate point in the output dataset INTREPID uses it for update INTREPID reports different locations for the same key and different keys for the same location as suspected errors Library Help Top 2012 Intrepid Geophysics Merged output dataset after process Lo ee aon 1 Group po O 2 Uoo 3 Roo 4 4 Back gt INTREPID User Manual Merging gravity datasets T56 2 Library Help Top lt 4 Back gt Using the Gravity Merge tool To use Gravity Merge with the INTREPID graphic user interface Note If you wish to identify duplicate locations with the same group by field usually station number we recommend that you use geographical coordinates latitude longitude These coordinates are superior for locating duplicate points spatially See Old Datum and Projection Conversion T12 for instructions on changing to this system 1 Choose Merge with Master from the Gravity menu in the Project Manager or use the command merge exe INTREPID displays the Gravity Merge window 2 Ifyou have previously prepared file specifications and parameter settings for Gravity Merge load the corresponding task specification file using Load Options from the File menu See Specifying input and output files for detailed instructions If all of the specifications are correct in this file go to step 6 If you wish to modify any settings carry out the following steps as required 3 Spec
Download Pdf Manuals
Related Search