# Weird behavior on Chebyshev

**URL:** <https://openfhe.discourse.group/t/weird-behavior-on-chebyshev/630>\
**Category:** Library Questions\
**Created:** [June 13, 2023, 6:07pm UTC](https://openfhe.discourse.group/t/weird-behavior-on-chebyshev/630 "2023-06-13T18:07:58Z")\
**Posts on this page:** 1\
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**Author:** ![ypolyakov](https://yyz1.discourse-cdn.com/flex031/user_avatar/openfhe.discourse.group/ypolyakov/32/47_2.png) [@ypolyakov](https://openfhe.discourse.group/u/ypolyakov)\
**Post date:** [June 14, 2023, 3:09am UTC](https://openfhe.discourse.group/t/weird-behavior-on-chebyshev/630/4 "2023-06-14T03:09:42Z")

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@marc-alonso Could you post your complete example here, including the cryptocontext parameters? `exp` grows fast with an argument (i.e., exponentially). It is important to know what multiplicative depth you are using. You may need room (extra levels) not to cause an overflow over your ciphertext/plaintext modulus when computing e^{10}, which is about 22,000.

Overall, it is not the best scenario for Chebyshev interpolation as you have both very small and very large values in this range, i.e., you would probably need a relatively large CKKS scaling factor for this case to achieve desired precision. Depending on your application, I would probably consider working in the logarithmic scale, i.e., switching the problem from exponential to linear.

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