> For the complete documentation index, see [llms.txt](https://docs.finngen.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.finngen.fi/working-in-the-sandbox/which-tools-are-available/trajectory-visualization-tool-tvt/viewing-atlas-co-and-genotype-cohorts-in-tvt.md).

# Viewing Atlas, CO, and Genotype cohorts in TVT

The Trajectory Visualization tool (TVT) can be used to view all the patients within cohorts prepared with [Atlas](/working-in-the-sandbox/which-tools-are-available/atlas.md), [Cohort Operations (CO)](/working-in-the-sandbox/which-tools-are-available/cohort-operations-tool-co.md), and [Genotype browser](/working-in-the-sandbox/working-with-genotype-data/genotype-browser.md).

In fact, TVT can be used to read in any cohort prepared with any tool (including R and Python) as long as the input file is correctly formed (as a tab-separated text file with a `FINNGENID` column, see [Running TVT](/working-in-the-sandbox/which-tools-are-available/trajectory-visualization-tool-tvt/trajectory-visualization-tool-tvt.md)).

### Visualizing Cohort Operations cohorts with TVT

Output files from CO can be uploaded directly to TVT.

To visualize a CO cohort with TVT, first [export the cohort from CO](/working-in-the-sandbox/which-tools-are-available/cohort-operations-tool-co/export-finngen-ids-using-co.md). Then open TVT and read the CO output file into TVT by clicking `Browse...` and selecting your CO output file from the folders.

![](/files/tryV6Njf8G5iE3o1Tafb)

Follow the instructions [here](/working-in-the-sandbox/which-tools-are-available/trajectory-visualization-tool-tvt/trajectory-visualization-tool-tvt.md) to view the data with TVT.

### Visualizing Atlas cohort with TVT

Atlas cohorts can be exported to TVT from the `Cohort` drop-down menu in `Data source`. TVT reads the cohort directly from Atlas.

Another way to view Atlas cohorts in TVT is to first [extract the cohort from Atlas using CO](/working-in-the-sandbox/which-tools-are-available/cohort-operations-tool-co/export-finngen-ids-using-co.md). Then open TVT and read the CO output file into TVT by clicking `Browse...` as above.

Follow the instructions [here](/working-in-the-sandbox/which-tools-are-available/trajectory-visualization-tool-tvt/trajectory-visualization-tool-tvt.md) to view the data with TVT.

### Visualizing Genotype browser cohorts with TVT

Output files from Genotype Browser can also be uploaded directly to TVT.

To visualize a Genotype cohort with TVT, first [output the genotype files using Genotype Browser](/working-in-the-sandbox/working-with-genotype-data/genotype-browser.md). TVT can then read the raw Genotype Browser output files - click `Browse...` as above.

You also have the option to pre-process Genotype cohorts with the Cohort Operations tool before loading them into TVT. CO can be used to combine Atlas and Genotype Browser cohorts, and cohorts from a text file, in flexible ways.

As an often-useful example, with the [Cohort Operations tool heterozygotes (0|1 and 1|0) can be combined](/working-in-the-sandbox/which-tools-are-available/cohort-operations-tool-co/combine-cohorts-with-co.md) to form one file of unphased heterozygotes.

Further, a phenotype cohort (e.g. patients with a given disease, defined in Atlas) can then be divided into groups of homozygotes and heterozygotes for a given variant [using CO](/working-in-the-sandbox/which-tools-are-available/cohort-operations-tool-co/combine-cohorts-with-co.md). With TVT pre-processed genotype cohorts [can then be visualized in a similar way as any CO cohort](#visualizing-cohort-operations-cohorts-with-tvt).

Follow the instructions [here](/working-in-the-sandbox/which-tools-are-available/trajectory-visualization-tool-tvt/trajectory-visualization-tool-tvt.md) to view the data with TVT.

You may also find [Example: Visualizing Genotype Browser output data with TVT](/working-in-the-sandbox/working-with-genotype-data/tools-for-geno-pheno-explorations/example-visualizing-genotype-browser-output-data-with-tvt.md) useful.