DIMFILTER(1gmt) | GMT | DIMFILTER(1gmt) |

*input_file.nc*- The data grid to be filtered.

**-D***distance_flag*- Distance
*flag*tells how grid (x,y) relates to filter*width*, as follows:*flag*= 0: grid (x,y) same units as*width*, Cartesian distances.*flag*= 1: grid (x,y) in degrees,*width*in kilometers, Cartesian distances.*flag*= 2: grid (x,y) in degrees,*width*in km, dx scaled by cos(middle y), Cartesian distances.*flag*= 3: grid (x,y) in degrees,*width*in km, dx scaled by cosine(y), Cartesian distance calculation.*flag*= 4: grid (x,y) in degrees,*width*in km, Spherical distance calculation.

**-F****x***width*[*mode*]- Sets the primary filter type. Choose among convolution and
non-convolution filters. Append the filter code
**x**followed by the full diameter*width*. Available convolution filters are:**b**) Boxcar: All weights are equal.**c**) Cosine Arch: Weights follow a cosine arch curve.**g**) Gaussian: Weights are given by the Gaussian function.**m**) Median: Returns median value.**p**) Maximum likelihood probability (a mode estimator): Return modal value. If more than one mode is found we return their average value. Append - or + to the filter width if you rather want to return the smallest or largest of the modal values.

**-N****x***sectors*- Sets the secondary filter type
**x**and the number of bow-tie sectors.*sectors*must be integer and larger than 0. When*sectors*is set to 1, the secondary filter is not effective. Available secondary filters are:**l**) Lower: Return the minimum of all filtered values.**u**) Upper: Return the maximum of all filtered values.**a**) Average: Return the mean of all filtered values.**m**) Median: Return the median of all filtered values.**p**) Mode: Return the mode of all filtered values.

**-G***output_file.nc**output_file.nc*is the output of the filter.

**-I***x_inc*[and optionally*y_inc*] is the output Increment. Append**m**to indicate minutes, or**c**to indicate seconds. If the new*x_inc*,*y_inc*are NOT integer multiples of the old ones (in the input data), filtering will be considerably slower. [Default: Same as input.]

**-R***west*,*east*,*south*, and*north*defines the Region of the output points. [Default: Same as input.]

**-T**- Toggle the node registration for the output grid so as to become the opposite of the input grid [Default gives the same registration as the input grid].

**-Q***cols**cols*is the total number of columns in the input text table file. For this mode, it expects to read depths consisted of several columns. Each column represents a filtered grid with a filter width, which can be obtained by**grd2xyz -Z**. The outcome will be median, MAD, and mean. So, the column with the medians is used to generate the regional component and the column with the MADs is used to conduct the error analysis.

**-V**[*level*] (more ...)- Select verbosity level [c].

**-f**[**i**|**o**]*colinfo*(more ...)- Specify data types of input and/or output columns.

**-^**or just**-**- Print a short message about the syntax of the command, then
exits (NOTE: on Windows just use
**-**).

**-+**or just**+**- Print an extensive usage (help) message, including the explanation of any module-specific option (but not the GMT common options), then exits.

**-?**or no arguments- Print a complete usage (help) message, including the explanation of all options, then exits.

June 26, 2017 | 5.4.2 |