# Data formatΒΆ

The data file you will need to feed to the fitter should contain one source per
line. Each line should contain `3*(n+1)`

columns, where `n`

is the number
of wavelengths/filters for which fluxes are given:

- Column
`1`

should contain the source name, with no spaces - Columns
`2`

and`3`

should contain the source coordinates - Columns
`4`

to`3+n`

should contain a flag for each flux, where the flag can take the following values:`0`

for data points which are not valid or used`1`

for valid data points`2`

for lower limits`3`

for upper limits`4`

for valid data points (as for`1`

) but where the fluxes and errors are expressed as and . This is useful for sources which have a magnitude with a large error, which can then be converted to and without worrying about the conversion from magnitude and magnitude error to linear fluxes and errors.

- Columns
`4+n`

to`3*(n+1)`

should contain the fluxes and flux uncertainties, alternated, in mJy. For lower and upper limits, the error should be set to the confidence placed on the limit, with 0 corresponding to 0% and 1 corresponding to 100%. For example, in the case of an upper limit, setting the confidence to 1 effectively forbids any models to be larger than the upper limit, while setting the confidence between 0 and 1 allows such models, but introduces a penalty dependent on the confidence. Setting the confidence to 0 effectively disables the upper limit.

We refer to this format as the **fitter data format**. Note that in a single
data file, all lines should have the same number of columns. If one or more
fluxes are not available for a specific source, the flag for these fluxes can
be set to `0`

.

An example data file with four fluxes per source is shown here:

```
SSTGLMC_G009.8925-00.3420 9.89250 -0.34200 1 1 1 1 6.869e+01 6.869e+00 1.512e+02 1.512e+01 1.626e+02 1.626e+01 9.015e+01 9.015e+00
SSTGLMC_G009.8940-00.3367 9.89408 -0.33675 0 0 1 1 -9.999e+02 -9.999e+02 -9.999e+02 -9.999e+02 7.412e+00 7.412e-01 1.199e+01 1.199e+00
SSTGLMC_G009.8943-00.3378 9.89430 -0.33783 0 0 1 1 -9.999e+02 -9.999e+02 -9.999e+02 -9.999e+02 4.462e+00 4.462e-01 6.927e+00 6.927e-01
```