# Type Float64 has no field head

**URL:** <https://discourse.julialang.org/t/type-float64-has-no-field-head/22897>\
**Category:** General Usage\
**Tags:** question\
**Created:** [April 8, 2019, 12:17am UTC](https://discourse.julialang.org/t/type-float64-has-no-field-head/22897 "2019-04-08T00:17:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Y\_Li](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/y_li/32/7573_2.png) [@Y\_Li](https://discourse.julialang.org/u/Y_Li)\
**Post date:** [April 8, 2019, 12:17am UTC](https://discourse.julialang.org/t/type-float64-has-no-field-head/22897/1 "2019-04-08T00:17:58Z")

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what does"type Float64 has no field head" means exactly?

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**Author:** ![JeffreySarnoff](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jeffreysarnoff/32/1980_2.png) [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Post date:** [April 8, 2019, 12:34am UTC](https://discourse.julialang.org/t/type-float64-has-no-field-head/22897/2 "2019-04-08T00:34:13Z")

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What did you do to get that message?

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<div class="post-metadata">

**Author:** ![Y\_Li](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/y_li/32/7573_2.png) [@Y\_Li](https://discourse.julialang.org/u/Y_Li)\
**Post date:** [April 8, 2019, 12:35am UTC](https://discourse.julialang.org/t/type-float64-has-no-field-head/22897/3 "2019-04-08T00:35:28Z")

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My bad, I just figured it out, there’s one constraint that really is just empty.