**Type**

Data Process.

**Behaviour**

It read a NetCDF file (both measure and dimensions). WARNING: It handles only mono-dimensional coordinate variables.

**Parameters**

src_path: path or OPeNDAP URL of the NetCDF file.

level: use:

- “0” to show the lists of dimensions, variables and attributes (default);
- “1” to show the values of a specific measure;
- “2” to show the values of a specific measure and the values of the corresponding dimensions.

schedule: scheduling algorithm. The only possible value is 0, for a static linear block distribution of resources.

measure: name of the measure related to the NetCDF file. The argument is mandatory in case level is different from “0”.

cdd: absolute path corresponding to the current directory on data repository. It is appended to

*BASE_SRC_PATH*to build the effective path to files (see configuration notes for further details).exp_dim: names of explicit dimensions. Multiple-value field: list of dimensions separated by “|” can be provided. It implicitly defines explicit dimension number and level (order). The argument is mandatory in case level is different from “0”.

imp_dim: names of implicit dimensions. Multiple-value field: list of dimensions separated by “|” can be provided. It implicitly defines implicit dimension number and level (order). Must be the same number of “imp_concept_level”. The argument is mandatory in case level is different from “0”.

subset_dims: dimension names used for the subsetting. Multiple-value field: list of dimensions separated by “|” can be provided; it must be the same number of “subset_filter”.

subset_filter: enumeration of comma-separated elementary filters (1 series of filters for each dimension). Possible forms are:

- start_value: single value specifying the start index of the subset
- start_value:stop_value => select elements from start_index to stop_index. Values should be numbers. Example: subset_dims=lat|lon;subset_filter=35:45|15:20.

Multiple-value field: list of filters separated by “|” can be provided; it must be the same number of “subset_dims”.

subset_type: if set to “index” (default), the subset_filter is considered on dimension index. With “coord”, filter is considered on dimension values.

limit_filter: optional filter on the maximum number of rows.

show_id: if “no” (default), it won’t show fragment row ID. With “yes”, it will also show the fragment row ID.

show_index: if “no” (default), it won’t show dimension ids. With “yes”, it will also show the dimension id next to the value.

show_time: if “no” (default), the values of time dimension are shown as numbers. With “yes”, the values are converted as a string with date and time.

show_stats: if one of the following mask is set, a list of statistics is returned for each time series; output data type is always “oph_double”. It can be adopted only in case only one implicit dimension exists.

- 00000000000000: no statistics (default)
- 1xxxxxxxxxxxxx: mean
- x1xxxxxxxxxxxx: variance
- xx1xxxxxxxxxxx: std dev
- xxx1xxxxxxxxxx: abs dev
- xxxx1xxxxxxxxx: skew
- xxxxx1xxxxxxxx: kurtosis
- xxxxxx1xxxxxxx: autocorrelation
- xxxxxxx1xxxxxx: max
- xxxxxxxx1xxxxx: min
- xxxxxxxxx1xxxx: 0.05 quantile
- xxxxxxxxxx1xxx: 0.25 quantile ->Q1
- xxxxxxxxxxx1xx: 0.5 quantile ->Q2 (median)
- xxxxxxxxxxxx1x: 0.75 quantile ->Q3
- xxxxxxxxxxxxx1: 0.95 quantile

show_fit: if “yes”, linear regression of each time serie is returned. It can be adopted only in case only one implicit dimension exists. With “no” (default), linear regression is not evaluated (default).

imp_num_points: indicates the number of points which measure values must be distribuited along by interpolation. If “imp_num_points” is higher than the number of actual points, then interpolation is evaluated; otherwise, “operation” is applied. It can be adopted only in case one implicit dimension exists. With “0”, no interpolation/reduction is applied (default).

offset: relative offset to be used to set reduction interval bounds (percentage). By default it is set to “50”; i.e. new values will be the centroids of reduction intervals.

operation: operation to be applied in case of reduction of the number of points. Possible values are: “max” to evaluate the maximum value; “min” to evaluate the minimum value; “avg” to evaluate the mean value (default); “sum” to evaluate the sum.

wavelet: used to apply wavelet filter provided “wavelet_points” is set. Possible values are:

- “yes”: original data and filtered data are returned
- “only”: only filtered data are returned
- “no”: only original data are returned (deafult)

wavelet_ratio: is the fraction of wavelet transform coefficients that are cleared by the filter (percentage). It can be adopted only in case one implicit dimension exists. With “0”, no compression is applied (default).

wavelet_coeff: if “yes”, wavelet coefficients are also shown; output data type is always “oph_double”; if necessary, their number is expanded to the first power of 2. It can be adopted only in case one implicit dimension exists.

**System parameters**

- exec_mode: operator execution mode. Possible values are async (default) for asynchronous mode, sync for synchronous mode with json-compliant output.
- ncores: number of parallel processes to be used (it must be 1).
- sessionid: session identifier used server-side to manage sessions and jobs. Usually, users don’t need to use/modify it, except when it is necessary to create a new session or switch to another one.
- objkey_filter: filter on the output of the operator written to file: “all” => no filter (default); “none” => no output; other values are:
- explorenc_data: show data or variable-dimension dependences (only for level 0)
- explorenc_summary: show a summary
- explorenc_dimvalues: show dimension values or dimension sizes (only for level 0)
- explorenc_wavelet_data: show wavelet transform
- explorenc_wavelet_coeff: show wavelet coefficients
- explorenc_stats: show a number of statistics on data
- explorenc_fit: show fitted data
- explorenc_metadata: show file attributes (only for level 0).

**Examples**

Read the NetCDF file /path/of/ncfile.nc:

```
[OPH_TERM] >> oph_explorenc measure=pressure;src_path=/path/of/ncfile.nc;exp_dim=lon|lat;imp_dim=time;
```

Argument name | Type | Mandatory | Values | Default | Min/Max-value |
---|---|---|---|---|---|

sessionid | “string” | “no” | “null” | ||

ncores | “int” | “no” | “1” | “1” / “1” | |

exec_mode | “string” | “no” | “async|sync” | “async” | |

src_path | “string” | “yes” | |||

level | “int” | “no” | “0|1|2” | “0” | “0” / “2” |

schedule | “int” | “no” | “0” | “0” | |

measure | “string” | “no” | |||

cdd | “string” | “no” | “/” | ||

exp_dim | “string” | “no” | |||

imp_dim | “string” | “no” | |||

subset_dims | “string” | “no” | “none” | ||

subset_type | “string” | “no” | “index|coord” | “index” | |

subset_filter | “string” | “no” | “all” | ||

limit_filter | “int” | “no” | “100” | “1” / “10000” | |

show_index | “string” | “no” | “yes|no” | “no” | |

show_id | “string” | “no” | “yes|no” | “no” | |

show_time | “string” | “no” | “yes|no” | “no” | |

show_stats | “string” | “no” | “00000000000000” | ||

show_fit | “string” | “no” | “yes|no” | “no” | |

imp_num_points | “int” | “no” | “0” | “0” / | |

offset | “real” | “no” | “50” | “0” / “100” | |

operation | “string” | “no” | “max|min|avg|sum” | “avg” | |

wavelet | “string” | “no” | “yes|no|only” | “no” | |

wavelet_ratio | “real” | “no” | “0” | “0” / “100” | |

wavelet_coeff | “string” | “no” | “yes|no” | “no” | |

objkey_filter | “string” | “no” | “all|none|explorenc_data|explorenc_summary|explorenc_dimvalues|explorenc_wavelet_data|explorenc_wavelet_coeff|explorenc_stats|explorenc_fit|explorenc_metadata” | “all” |