# Exact numerical representation **URL:** \ **Category:** Help & Support\ **Created:** [July 24, 2025, 11:54am UTC](https://www.alphagenomecommunity.com/t/exact-numerical-representation/508 "2025-07-24T11:54:16Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Zoran\_Kostic](https://yyz2.discourse-cdn.com/watermelon/user_avatar/www.alphagenomecommunity.com/zoran_kostic/32/406_2.png) [@Zoran\_Kostic](https://www.alphagenomecommunity.com/u/Zoran_Kostic)\ **Post date:** [July 24, 2025, 11:54am UTC](https://www.alphagenomecommunity.com/t/exact-numerical-representation/508/1 "2025-07-24T11:54:16Z")
What is the exact numerical format for representing a base pair (as in byte/ integer8 or similar)? ---
**Author:** ![tward](https://yyz2.discourse-cdn.com/watermelon/user_avatar/www.alphagenomecommunity.com/tward/32/17_2.png) [@tward](https://www.alphagenomecommunity.com/u/tward)\ **Post date:** [July 24, 2025, 7:54pm UTC](https://www.alphagenomecommunity.com/t/exact-numerical-representation/508/2 "2025-07-24T19:54:49Z")
Hi @Zoran_Kostic , welcome to the community! I assume you mean what we pass to the model representing the DNA sequence? We pass that as a 1-hot encoded, float32 array. The shape we use is `[B, S, 4]`, where B=number of examples, S=sequence length (e.g. 1Mb) and 4 being the A, C, G, T 1-hot encoding (e.g. `[1, 0, 0, 0]` for A); and all zeros represents N’s. ---
**Author:** ![David\_Yuan](https://yyz2.discourse-cdn.com/watermelon/user_avatar/www.alphagenomecommunity.com/david_yuan/32/518_2.png) [@David\_Yuan](https://www.alphagenomecommunity.com/u/David_Yuan)\ **Post date:** [September 1, 2025, 7:21am UTC](https://www.alphagenomecommunity.com/t/exact-numerical-representation/508/3 "2025-09-01T07:21:11Z")
Does that mean other letters in the IUPAC table are not supported ( [IUPAC Codes](https://www.bioinformatics.org/sms/iupac.html) )? I was also wondering if any forms of methylation, which may play significant roles are not considered at the moment?