| 50 | | ---- |
| 51 | | '''EXAMPLE ON USAGE OF THE FLEXtest''' '''' |
| 52 | | |
| 53 | | The file '''{{{FlexpartErrors/test/test_FlexpartErrors.py}}}''' contains a variety of test cases which can serve as examples on how to use this class. However, the following is intended to be a more user-friendly introduction. Be sure fist to set your '''{{{$PYTHONPATH}}}''' correctly. If you have put the testing environment in directory {{{/home/mememe/flexpart-testing}}} you would set your '''{{{$PYTHONPATH}}}''' in the bash shell as follows |
| 54 | | |
| 55 | | {{{ |
| 56 | | export PYTHONPATH=/home/mememe/flexpart-testing:$PYTHONPATH |
| 57 | | }}} |
| 58 | | |
| 59 | | The data used in these examples come from a tiny, nested outgrid of 4 rows, 3 columns, 5 levels, 2 species, 6 releases and 1 age class in the mother domain. In the nest, there are 10 rows and 5 columns of grid points. The control model comes from a simulation using ECMWF met data, and the test run comes from the same simulation using NCEP met data. There are three timestamps: |
| 60 | | |
| 61 | | {{{ |
| 62 | | ['20140919010000', '20140919020000', '20140919030000'] |
| 63 | | }}} |
| 64 | | |
| 65 | | The test data here is available in the '''{{{unittest_data}}}''' directory of the code distribution. As a first example, let's get a grid that represents the difference (test minus control) between the two datasets, under various conditions. First, we create the !FlexpartOutput objects as follows. You will need to change the value of '''{{{DATA_DIR}}}''' to the location of your distribution. |
| 66 | | |
| 67 | | {{{ |
| 68 | | import flexread.FlexpartOutput as flexout |
| 69 | | import FlexpartErrors as flexerr |
| 70 | | |
| 71 | | DATA_DIR='/u1/uaf/morton/flexpart-testing/unittest_data' |
| 72 | | |
| 73 | | CONTROL_OUTPUT_DIR = DATA_DIR + '/flexout_forward_tiny_complex_withnest' |
| 74 | | TEST_OUTPUT_DIR = DATA_DIR + '/ncepflexout_forward_tiny_complex_withnest' |
| 75 | | |
| 76 | | # Create the two objects used for containing the FLEXPART output |
| 77 | | # By default, this will point to the mother nest of the domains. |
| 78 | | control_output = flexout.FlexpartOutput(output_dir=CONTROL_OUTPUT_DIR) |
| 79 | | test_output = flexout.FlexpartOutput(output_dir=TEST_OUTPUT_DIR) |
| 80 | | |
| 81 | | # Create the error object |
| 82 | | error_obj = flexerr.FlexpartErrors(control=control_output, |
| 83 | | test=test_output) |
| 84 | | |
| 85 | | # Get the diff_grid from default parameters |
| 86 | | diff_grid = error_obj.get_diff_grid() |
| 87 | | |
| 88 | | print diff_grid |
| 89 | | }}} |
| 90 | | |
| 91 | | In the above, we create '''{{{control_output}}}''' and '''{{{test_output}}}''' objects, then create an '''{{{error_obj}}}''' object by initialising with these two objects. With no arguments to the '''{{{diff_grid}}}''' method, we use default values, giving us a horizontal slice at level 1, for a roughly middle timestamp |
| 92 | | |
| 93 | | {{{ |
| 94 | | [[ 0. 0. 0. ] |
| 95 | | [ 0. -0.09765793 0. ] |
| 96 | | [ 0. 0.18723705 0. ] |
| 97 | | [ 0. 0. 0. ]] |
| 98 | | }}} |
| 99 | | |
| 100 | | Exercising a little more specificity, in the next case we get the diff grid from last timestamp, 20140919030000, level 2, species 1, release 5, as follows |
| 101 | | |
| 102 | | {{{ |
| 103 | | diff_grid = error_obj.get_diff_grid(timestamp='20140919030000', |
| 104 | | level=2, |
| 105 | | species=1, |
| 106 | | release=5 |
| 107 | | ) |
| 108 | | |
| 109 | | print diff_grid |
| 110 | | }}} |
| 111 | | |
| 112 | | |
| 113 | | {{{ |
| 114 | | [[ 0.00000000e+00 0.00000000e+00 0.00000000e+00] |
| 115 | | [ -2.90811108e-02 -6.62608682e-05 0.00000000e+00] |
| 116 | | [ -1.18361338e-01 -8.55133458e-05 0.00000000e+00] |
| 117 | | [ 0.00000000e+00 0.00000000e+00 0.00000000e+00]] |
| 118 | | }}} |
| 119 | | |
| 120 | | Up to now, we have used the ''get_diff_grid()'' method to illustrate how to access different components of the output files. In most cases, the user will not even use ''get_diff_grid()'' unless he or she wants more detail. This !FlexpartErrors class is used primarly to calculate the error between two grids. The available methods are described in http://flexpart.eu:8088/svn/CTBTOdevel/trunk/flexpart-testing/doc |
| 121 | | |
| 122 | | In the following example we go through the calculation of errors on different portions of the output grids for the nest |
| 123 | | |
| 124 | | {{{ |
| 125 | | import flexread.FlexpartOutput as flexout |
| 126 | | import FlexpartErrors as flexerr |
| 127 | | |
| 128 | | DATA_DIR='/u1/uaf/morton/flexpart-testing/unittest_data' |
| 129 | | |
| 130 | | CONTROL_OUTPUT_DIR = DATA_DIR + '/flexout_forward_tiny_complex_withnest' |
| 131 | | TEST_OUTPUT_DIR = DATA_DIR + '/ncepflexout_forward_tiny_complex_withnest' |
| 132 | | |
| 133 | | # Create the two objects used for containing the FLEXPART output |
| 134 | | # By default, this will point to the mother nest of the domains. |
| 135 | | control_output = flexout.FlexpartOutput(output_dir=CONTROL_OUTPUT_DIR, |
| 136 | | nest=True) |
| 137 | | test_output = flexout.FlexpartOutput(output_dir=TEST_OUTPUT_DIR, |
| 138 | | nest=True) |
| 139 | | |
| 140 | | # Create the error object |
| 141 | | error_obj = flexerr.FlexpartErrors(control=control_output, |
| 142 | | test=test_output) |
| 143 | | |
| 144 | | # Calculate mean bias for the default time and horizontal slice of the next |
| 145 | | bias = error_obj.mean_bias() |
| 146 | | print 'Mean bias for default horizontal slice: ' + str(bias) |
| 147 | | |
| 148 | | # Calculate the max error (max magnitude, whether positive or negative) of |
| 149 | | # the entire time series and entire volume for species 2, release 1 |
| 150 | | maxerr = error_obj.max_error(species=2, release=1, |
| 151 | | volume=True, timeseries=True) |
| 152 | | print 'Max error for full timeseries and volume, species 2, release 1: ' + \ |
| 153 | | str(maxerr) |
| 154 | | |
| 155 | | # Calculate the RMSE of last timestep, level 2, for species 1, release 2 |
| 156 | | rmse = error_obj.rmse(timestamp='20140919030000', level=2, |
| 157 | | species=1, release=2) |
| 158 | | print 'RMSE for level 2, species 1, release 2, last timestamp: ' + \ |
| 159 | | str(rmse) |
| 160 | | }}} |
| 161 | | |
| 162 | | |
| 163 | | {{{ |
| 164 | | Mean bias for default horizontal slice: 0.0449703330779 |
| 165 | | Max error for full timeseries and volume, species 2, release 1: 3.79051153362 |
| 166 | | RMSE for level 2, species 1, release 2, last timestamp: 0.146961582495 |
| 167 | | }}} |
| 168 | | |
| 169 | | |
