# I can't run lefse tutorial example **URL:** \ **Category:** LEfSe\ **Created:** [June 1, 2021, 8:23pm UTC](https://forum.biobakery.org/t/i-cant-run-lefse-tutorial-example/2183 "2021-06-01T20:23:48Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Rodrigo\_Peralta](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/rodrigo_peralta/32/666_2.png) [@Rodrigo\_Peralta](https://forum.biobakery.org/u/Rodrigo_Peralta)\ **Post date:** [June 1, 2021, 8:23pm UTC](https://forum.biobakery.org/t/i-cant-run-lefse-tutorial-example/2183/1 "2021-06-01T20:23:48Z")
I downloaded this example: [https://github.com/biobakery/biobakery/raw/master/demos/biobakery\_demos/data/lefse/input/hmp\_small\_aerobiosis.txt](https://github.com/biobakery/biobakery/raw/master/demos/biobakery_demos/data/lefse/input/hmp_small_aerobiosis.txt) After that i run this: format\_input.py hmp\_aerobiosis\_small.txt hmp\_aerobiosis\_small.in -c 1 -s 2 -u 3 -o 1000000 and obtain this error: Traceback (most recent call last): File “/home/rodrigo/miniconda3/envs/lefse/bin/lefse-format\_input.py”, line 459, in feats = numerical\_values(feats,params[‘norm\_v’]) File “/home/rodrigo/miniconda3/envs/lefse/bin/lefse-format\_input.py”, line 191, in numerical\_values feats[k] = [float(val) for val in v] File “/home/rodrigo/miniconda3/envs/lefse/bin/lefse-format\_input.py”, line 191, in feats[k] = [float(val) for val in v] ValueError: could not convert string to float: ‘skin’ ---
**Author:** ![mishort](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/mishort/32/556_2.png) [@mishort](https://forum.biobakery.org/u/mishort)\ **Post date:** [June 4, 2021, 4:49pm UTC](https://forum.biobakery.org/t/i-cant-run-lefse-tutorial-example/2183/2 "2021-06-04T16:49:39Z")
Hi Rodrigo, Would you mind letting me know how you set the class and subclass variables? I think that might be causing this error. Thanks, Meg