MODE config file generator


In the first table below are the config file parameters that most users will need to change. Following this are more tables with parameters grouped according to function.

After each table there is a "Submit" button. Clicking any one of them should return a config file to you, unless there is an error. In that case, use your browser's "Back" button to return to this page and fix the problem.


Basic Parameters


Name Input value Explanation
Model Identifies the name to be assigned to the model being verified. This text string is written out in the first column of the ASCII output so that verification statistics from multiple models may be differentiated.
Grid Resolution The nominal spacing for each grid square in kilometers. The variable is not used directly in the code, but subsequent variables in the configuration file are defined in terms of it. Therefore, setting this appropriately will help ensure that appropriate default values are used for these variables.
Forecast Field Specifies the model variable and the corresponding vertical level to be verified. The GRIB code itself or the corresponding abbreviation may be used to specify which model field is to be verified. A slash and a level indicator in the form ANNN, ZNNN, or PNNN must follow each GRIB code. The level indicators correspond to an accumulation interval (A), a single vertical level (Z), or a single pressure level (P). NNN indicates the accumulation or level value.
Obs Field Specifies the Obervation variable. See above.
Forecast Convolution Radius Defines the radius of the circular convolution applied to smooth the raw fields. The radius is specified in terms of grid units.
Obs Convolution Radius See above.
Forecast Convolution Threshold Specifies the threshold values to be applied to the convolved field to define objects. The thresholds are specified using the Fortran conventions of gt, ge, eq, ne, lt, le.
Obs Convolution Threshold See above.
Forecast Merge Flag The fcst_merge_flag and obs_merge_flag variable control what type of merging techniques will be applied to the objects defined in each field.
Obs Merge Flag
Match Flag The match_flag variable controls how matching will be performed when comparing objects from the forecast field to objects from the observation field. An interest value is computed for each possible pair of forecast/observation objects. The interest values are then thresholded to define which objects match. If two objects in one field happen to match the same object in the other field, then those two objects could be merged. The match_flag controls what type of merging is allowed in this context.
Total Interest Threshold Should be set between 0 and 1. This threshold is applied to the total interest values computed for each pair of objects. Object pairs that have an interest value that is above this threshold will be matched, while those with an interest value that is below this threshold will remain unmatched. Increasing the threshold will decrease the number of matches while decreasing the threshold will increase the number of matches.




Matching, merging, grid and masking parameters


Name Input value Explanation
Mask Missing Flag Specifies how missing data in the raw model and observation fields will be treated.
Mask Grid Specifies a pre-defined NCEP grid with which to mask the raw forecast and observation fields. The predefined grids are specified as GNNN where NNN is the three digit designation for the grid. By default, no masking grid is applied.
Mask Grid Flag Specifies how the mask_grid should be applied. By default, the masking grid is not applied.
Mask Polyline Specifies the name of a file that defines a lat/lon polygon to be used in masking the raw forecast and observation fields. Several masking polygons used by NCEP are predefined in the data/poly subdirectory of the MET distribution. Users can easily define and apply new masking polygons similar to the predefined ones. By default, no masking polygons are used. Similar to the mask_grid variable above.
Mask Polyline Flag Specifies how the masking polygon should be applied. Similar to the mask_grid_flag variable above.
Forecast Raw Threshold Used to threshold the raw fcst field. Thresholds are specified using the Fortran conventions of gt, ge, eq, ne, lt, le to indicate greater than, greater than or equal to, equal to, not equal to, less than, and less than or equal to, respectively. By default, the raw fields are thresholded greater than or equal to zero.
Obs Raw Threshold See above.
Bad Data Threshold Must be between 0 and 1. When performing the circular convolution step if the proportion of bad data values in the convolution area is greater than or equal to this threshold, the resulting convolved value will be set to "bad data". If the proportion is less than this threshold, the convolution will be performed on only the valid data.
Forecast Area Threshold Specifies the area threshold values to be applied to the defined objects.
Obs Area Threshold See above.
Forecast Intensity Percent The fcst_inten_perc, fcst_inten_perc_threshold, obs_inten_perc, and obs_inten_perc_threshold variables specify the intensity threshold values to be applied to the defined objects. For each object defined, the intensity values within the object are sorted, and the requested intensity percentile value is computed. By default, the maximum value is computed since the intensity percentiles are set to 100. Any objects with an intensity percentile that does not meet the corresponding intensity percentile threshold specified will be discarded.
Forecast Intensity Percent Threshold
Obs Intensity Percent
Obs Intensity Percent Threshold
Forecast Merge Threshold The fcst_merge_threshold and obs_merge_threshold variables are used to define larger objects for use in merging the original objects. These variables define the threshold value used in the double thresholding merging technique. Note that in order to use this merging technique, it must be requested using the fcst_merge_flag and obs_merge_flag. These thresholds should be chosen to define larger objects which fully contain the originally defined objects.
Obs Merge Threshold




Attribute weights and related items


Name Input value Explanation
Maximum Centroid Distance Computing the attributes for all possible pairs of objects can take some time depending on the numbers of objects. The max_centroid_dist variable is used to specify how far apart objects should be in order to conclude that they have no chance of matching. No pairwise attributes are computed for pairs of objects whose centroids are farther away than this distance, defined in terms of grid units. Setting this variable to a reasonable value will improve the execution time of the MODE tool
Centroid Distance Weight The weight variables control how much weight is assigned to each pairwise attribute when computing a total interest value for object pairs.
Boundary Distance Weight
Hull Distance Weight
Angle Difference Weight
Area Ratio Weight
Int Area Ratio Weight
Complexity Ratio Weight
Intensity Ratio Weight
Intensity Percentile The intensity_percentile variable corresponds to the intensity_ratio_weight variable listed above. The intensity_percentile should be set between 0 and 100 to define which percentile of intensity should be compared for pairs of objects. By default, the 50th percentile, or median value, is chosen.




Interest functions and confidence maps

Note that for algebraic expressions, the independent variable is always "x"


Name Input value Explanation
Centroid Distance Interest Function The interest function variables define which values are of interest for each pairwise attribute measured.
Boundary Distance Interest Function
Hull Distance Interest Function
Angle Difference Interest Function
Area Ratio Interest Function
Int Area Ratio Interest Function
Complexity Ratio Interest Function
Intensity Ratio Interest Function
Aspect Ratio Confidence Map Defines a confidence function applied to the angle difference attribute.
Area Ratio Confidence Map Defines a confidence function applied to the centroid distance attribute.




Plotting Information


Name Input value Explanation
Met Data Directory The MODE tool uses several static data files when generating plots. If it cannot find the data it needs in the expected directory, it will error out. The met_data_dir variable may be set to the path that contains the data/ subdirectory of the top-level MET directory to instruct MODE where to find the static data files.
Forecast Raw Colortable The fcst_raw_color_table, obs_raw_color_table and mode_color_table variables indicate which color table files are to be used when generating the output PostScript plot. The forecast and observation raw field are plotted using values in the fcst_raw_color_table and obs_raw_color_table, while the objects identified are plotted using the values in the mode_color_table.
Obs Raw Colortable
Mode Color Table
Fcst Raw Plot Min These variables indicate the min and max data values to be plotted for the forecast and observation fields. If set to non-zero values, the forecast and observation raw color tables specified above will be rescaled to match the specified range.
Fcst Raw Plot Max
Obs Raw Plot Min
Obs Raw Plot Max
Stride Length The MODE tool generates a color bar to represent the contents of the colorable that was used to plot a field of data. The number of entries in the color bar matches the number of entries in the color table. The values defined for each color in the color table are also plotted next to the color bar. The stride_length variable is used to define the frequency with which the color table values should be plotted. Setting this variable to 1 indicates that every color table value should be plotted. Setting it to an integer, n > 1, indicates that only every nth color table value should be plotted.
Zero Border Size The MODE tool is not able to define objects that touch the edge of the grid. After the convolution step is performed the outer columns and rows of data are zeroed out to enable MODE to identify objects. The zero_border_size variable specifies how many outer columns and rows of data are to be zeroed out.
Plot Valid Flag Indicates the region which should be plotted.
Plot GC Arc Flag Specifies whether polylines should be plotted using straigt lines on the grid, or using great circle arcs.




Miscellaneous items


Name Input value Explanation
Print Interest Threshold Determines which pairs of object attributes will be written to the output object attribute ASCII file. The user may choose to set the print_interest_threshold to the same value as the total_interest_threshold, meaning that only object pairs which actually match are written to the output file.
GRIB PTV Sets the GRIB table 2 parameter version, and thus indicates how to interpret GRIB codes between 128 and 255.
Output Prefix Specifies a string to be used in the output file name. It can be useful for keeping results for different models or variables from overwriting each other.