# Gadfly ERROR: MethodError: no method matching evalmapping(::DataFrame, ::Measures.Length{:mm,Float64})

**URL:** <https://discourse.julialang.org/t/gadfly-error-methoderror-no-method-matching-evalmapping-dataframe-measures-length-mm-float64/51754>\
**Category:** New to Julia\
**Tags:** plotting, gadfly\
**Created:** [December 13, 2020, 3:19am UTC](https://discourse.julialang.org/t/gadfly-error-methoderror-no-method-matching-evalmapping-dataframe-measures-length-mm-float64/51754 "2020-12-13T03:19:18Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![nsajko](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nsajko/32/221187_2.png) [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Post date:** [December 13, 2020, 3:19am UTC](https://discourse.julialang.org/t/gadfly-error-methoderror-no-method-matching-evalmapping-dataframe-measures-length-mm-float64/51754/1 "2020-12-13T03:19:18Z")

</div>

Can somebody explain the error I get when running this:

```julia
draw(SVG("/tmp/ex.svg", 30cm, 20cm), plot(layer(DataFrame(x=[1, 2, 3], y=[5, 6, 9]), x=:x, y=:y, size=1pt, Geom.point, Theme(highlight_width=0pt))))

```

```julia
ERROR: MethodError: no method matching evalmapping(::DataFrame, ::Measures.Length{:mm,Float64})
Closest candidates are:
  evalmapping(::AbstractDataFrame, ::Symbol) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/dataframes.jl:68
  evalmapping(::AbstractDataFrame, ::AbstractString) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/dataframes.jl:69
  evalmapping(::AbstractDataFrame, ::Integer) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/dataframes.jl:70
  ...
Stacktrace:
 [1] _evalmapping!(::Dict{Symbol,Any}, ::DataFrame, ::Gadfly.Data) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/mapping.jl:204
 [2] evalmapping!(::Dict{Symbol,Any}, ::DataFrame, ::Gadfly.Data) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/mapping.jl:233
 [3] render_prepare(::Plot) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/Gadfly.jl:414
 [4] render(::Plot) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/Gadfly.jl:740
 [5] draw(::SVG, ::Plot) at /home/nsajko/.julia/packages/Gadfly/Xnkmc/src/Gadfly.jl:847
 [6] top-level scope at REPL[2]:1
 [7] run_repl(::REPL.AbstractREPL, ::Any) at /build/julia/src/julia-1.5.3/usr/share/julia/stdlib/v1.5/REPL/src/REPL.jl:288

```

---

<div class="post-metadata">

**Author:** ![nsajko](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nsajko/32/221187_2.png) [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Post date:** [December 13, 2020, 3:31am UTC](https://discourse.julialang.org/t/gadfly-error-methoderror-no-method-matching-evalmapping-dataframe-measures-length-mm-float64/51754/2 "2020-12-13T03:31:17Z")

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This is it: `size=[1pt]` must be used.