Output to LaTeX added (useful for IJulia notebook export to PDF)

src/abstractdataframe/io.jl

@@ -200,6 +200,60 @@ end
     write(io, "</table>")
 end
 
+##############################################################################
+#
+# LaTeX output
+#
+##############################################################################
+
+function latex_char_escape(char::SubString)
+    if char == "\\"
+        return "\\textbackslash{}"
+    elseif char == "~"
+        return "\\textasciitilde{}"
+    else
+        return string("\\", char)
+    end
+end
+
+function latex_escape(cell::AbstractString)
+    cell = replace(cell, ['\\','~','#','$','%','&','_','^','{','}'], latex_char_escape)
+    return cell
+end
+
+function Base.show(io::IO, ::MIME"text/latex", df::AbstractDataFrame)
+    nrows = size(df, 1)
+    ncols = size(df, 2)
+    cnames = _names(df)
+    alignment = repeat("c", ncols)
+    write(io, "\\begin{tabular}{r|")
+    write(io, alignment)
+    write(io, "}\n")
+    write(io, "\t& ")
+    header = join(map(c -> latex_escape(string(c)), cnames), " & ")
+    write(io, header)
+    write(io, "\\\\ \n")
+    write(io, "\t\\hline \n")
+    for row in 1:nrows
+        write(io, "\t")
+        write(io, @sprintf("%d", row))
+        for col in 1:ncols
+            write(io, " & ")
+            cell = df[row,col]
+            if !isnull(cell)
+                content = get(cell)
+                if mimewritable(MIME("text/latex"), content)
+                    show(io, MIME("text/latex"), content)
+                else
+                    print(io, latex_escape(string(content)))
+                end
+            end
+        end
+        write(io, " \\\\ \n")
+    end
+    write(io, "\\end{tabular}\n")
+end
+
 ##############################################################################
 #
 # MIME

test/REQUIRE

@@ -2,3 +2,4 @@ Compat 0.9.0
 DataStructures
 RDatasets # can be removed when deprecated.jl doesn't test read_rda anymore
 RData
+LaTeXStrings

test/io.jl

@@ -1,6 +1,7 @@
 module TestIO
     using Base.Test
     using DataFrames, Compat
+    using LaTeXStrings
 
     #test_group("We can read various file types.")
 
@@ -490,4 +491,13 @@ module TestIO
     # Need to wrap macro call inside eval to prevent the error from being
     # thrown prematurely
     @test_throws ArgumentError eval(:(csv"foo,bar"a))
+
+    # Test LaTeX export
+    df = DataFrame(A = 1:4, 
+                   B = ["\$10.0", "M&F", "A~B", "\\alpha"], 
+                   C = [L"\alpha", L"\beta", L"\gamma", L"\sum_{i=1}^n \delta_i"],
+                   D = [1.0, 2.0, Nullable(), 3.0]
+                   )
+    @test isequal(reprmime(MIME("text/latex"), df), "\\begin{tabular}{r|cccc}\n\t& A & B & C & D\\\\ \n\t\\hline \n\t1 & 1 & \\\$10.0 & \$\\alpha\$ & 1.0 \\\\ \n\t2 & 2 & M\\&F & \$\\beta\$ & 2.0 \\\\ \n\t3 & 3 & A\\textasciitilde{}B & \$\\gamma\$ &  \\\\ \n\t4 & 4 & \\textbackslash{}alpha & \$\\sum_{i=1}^n \\delta_i\$ & 3.0 \\\\ \n\\end{tabular}\n")
+
 end