# [racket] TR+plot exposes idx9, idx54, etc?

Here’s a short piece of code that tries to plot an array:
#lang typed/racket
(require plot
math/array)
(define fft-maxes (array #[3.2 978.9 -2397]))
(: with-indexes (Vectorof (Vector Nonnegative-Integer Real)))
(define with-indexes
(for/vector : (Vectorof (Vector Nonnegative-Integer Real))
([i : Nonnegative-Integer (in-naturals)]
[a (in-array fft-maxes)])
(ann (vector (ann i Nonnegative-Integer) a)
(Vector Nonnegative-Integer Real))))
(plot (lines (in-vector with-indexes)))
I have two questions.
1) Is there an easier way to pair an array with indices? This was kind of challenging.
2) When I run this, I get
Type Checker: missing type for identifier;
consider using `require/typed' to import it
identifier: idX9
from module: plot in: #%module-begin
. Type Checker: missing type for identifier;
consider using `require/typed' to import it
identifier: idX54
from module: plot/no-gui in: #%module-begin
. Type Checker: Summary: 2 errors encountered in:
#%module-begin
#%module-begin
It seems like I shouldn’t really be trying to make up types for generated identifiers; what’s the right way to solve this?
Thanks!
John Clements