# JuMP @constraint - "begin end" block not working

**URL:** <https://discourse.julialang.org/t/jump-constraint-begin-end-block-not-working/49734>\
**Category:** Optimization (Mathematical)\
**Tags:** question, jump, pluto\
**Created:** [November 7, 2020, 11:45am UTC](https://discourse.julialang.org/t/jump-constraint-begin-end-block-not-working/49734 "2020-11-07T11:45:15Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![shashankchahar](https://avatars.discourse-cdn.com/v4/letter/s/ee59a6/32.png) [@shashankchahar](https://discourse.julialang.org/u/shashankchahar)\
**Post date:** [November 7, 2020, 11:45am UTC](https://discourse.julialang.org/t/jump-constraint-begin-end-block-not-working/49734/1 "2020-11-07T11:45:15Z")

</div>

Hi,

I am trying to set some constraints in JuMP within Pluto. If I specify each constraint on a separate line then I don’t get an error message but if I try to put all the constraints in a begin-end block then Pluto gives me the following error.

```julia
LoadError: At C:\Users\shash\Documents\Actuarial\Julia\MA_FS\calibrating_trans_matrix.jl#==#ed816000-2055-11eb-273a-f1207b058a14:31: `@constraint(model, begin

#= C:\Users\shash\Documents\Actuarial\Julia\MA_FS\calibrating_trans_matrix.jl#==#ed816000-2055-11eb-273a-f1207b058a14:32 =#

(default_col[i = 1:7], x[i, 8] == pd_table[1, i])

#= C:\Users\shash\Documents\Actuarial\Julia\MA_FS\calibrating_trans_matrix.jl#==#ed816000-2055-11eb-273a-f1207b058a14:33 =#

(default_row[i = 1:7], x[8, i] == 0)

#= C:\Users\shash\Documents\Actuarial\Julia\MA_FS\calibrating_trans_matrix.jl#==#ed816000-2055-11eb-273a-f1207b058a14:34 =#

(default_row[8], x[8, 8] == 1)

#= C:\Users\shash\Documents\Actuarial\Julia\MA_FS\calibrating_trans_matrix.jl#==#ed816000-2055-11eb-273a-f1207b058a14:35 =#

(sum_of_rows[i = 1:8], sum(x[i, :]) == 1)

end)`: Code block passed as constraint. Perhaps you meant to use @constraints instead?

in expression starting at C:\Users\shash\Documents\Actuarial\Julia\MA_FS\calibrating_trans_matrix.jl#==#ed816000-2055-11eb-273a-f1207b058a14:31

error(::String, ::String)@error.jl:42
_macro_error(::Symbol, ::Array{Any,1}, ::LineNumberNode, ::String)@macros.jl:924
(::JuMP.var"#_error#73"{Symbol,LineNumberNode})(::String)@macros.jl:390
_constraint_macro(::Tuple{Symbol,Expr}, ::Symbol, ::typeof(JuMP.parse_constraint_expr), ::LineNumberNode)@macros.jl:424
@constraint(::LineNumberNode, ::Module, ::Vararg{Any,N} where N)@macros.jl:514

```

My code is as follows:

```julia
function calibrate_trans_rate(filepath_pd)
	
	# Get PD values
	pd_table = zeros(Float64, 30, 7)
	open(filepath_pd, "r") do fp
		for row in 1:30
			line = readline(fp)
			pd_table[row, :] .= parse.(Float64, split(line, ",")) 
		end
	end

	# Set up solver
	model = Model() # need to decide what solver to use
	
	# Set variable to be transition values
	@variable(model, 0 <= x[1:8, 1:8] <= 1)
	
	### This works
	# Default column is known
	#@constraint(model, default_col[i = 1:7], x[i, 8] == pd_table[1, i])
	
	# Default row is known
	#@constraint(model, default_row[i = 1:7], x[8, i] == 0)
	#@constraint(model, default_row[8], x[8, 8] == 1)
	
	# Sum of all row is equal to 1 (probabilities)
	#@constraint(model, sum_of_rows[i = 1:8], sum(x[i, :]) == 1)
	
	###
	
	@constraint(model, begin
			default_col[i = 1:7], x[i, 8] == pd_table[1, i]
			default_row[i = 1:7], x[8, i] == 0
			default_row[8], x[8, 8] == 1
			sum_of_rows[i = 1:8], sum(x[i, :]) == 1
		end)
	
	# Define statistic to minimize
	
	# Calculate holdings at various year
	x_power = [x^i for i = 1:30]
	
	# Calculate sum of squared difference between calibrated PD and actual PD
	sum_of_sq_diff = sum((x_power[i][1:7, 8] - pd_table[2, :]).^2)
	
	@objective(model, Min, sum_of_sq_diff)
	
	JuMP.optimize!(model)

    obj_value = JuMP.objective_value(model)
    trans_matrix = JuMP.value(x)
end

```

Any idea what I am doing wrong?

---

<div class="post-metadata">

**Author:** ![metab0t](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/metab0t/32/15551_2.png) [@metab0t](https://discourse.julialang.org/u/metab0t)\
**Post date:** [November 7, 2020, 1:33pm UTC](https://discourse.julialang.org/t/jump-constraint-begin-end-block-not-working/49734/2 "2020-11-07T13:33:34Z")

</div>

Try using `@constraints` instead.

---

<div class="post-metadata">

**Author:** ![shashankchahar](https://avatars.discourse-cdn.com/v4/letter/s/ee59a6/32.png) [@shashankchahar](https://discourse.julialang.org/u/shashankchahar)\
**Post date:** [November 7, 2020, 5:14pm UTC](https://discourse.julialang.org/t/jump-constraint-begin-end-block-not-working/49734/3 "2020-11-07T17:14:54Z")

</div>

> [@shashankchahar](#):
>
> `Perhaps you meant to use @constraints instead?`

Sorry, new to programming - the answer was right there:

“Perhaps you meant to use @constraints instead?”