Re: How to remove external parentheses from a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg131524] Re: How to remove external parentheses from a list*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sat, 17 Aug 2013 02:07:43 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130816110619.E9E426A0D@smc.vnet.net>

Use Sequence limits = {{x1, a, b}, {x2, c, d}, {xn, y, z}}; Integrate[f[x1, x2, xn], Sequence @@ limits] Integrate[f[x1, x2, xn], {x1, a, b}, {x2, c, d}, {xn, y, z}] However, Mathematica only accepts this form because Integrate does not have the Attribute HoldAll or HoldRest. Attributes[Integrate] {Protected, ReadProtected} For functions that have either of these attributes, you would also need to use Evaluate. Attributes[Table] {HoldAll, Protected} limits = {{x1, 0, 1}, {x2, 0, 1}, {xn, 0, 1}}; Table[f[x1, x2, xn], Evaluate[Sequence @@ limits]] // Flatten {f[0, 0, 0], f[0, 0, 1], f[0, 1, 0], f[0, 1, 1], f[1, 0, 0], f[1, 0, 1], f[1, 1, 0], f[1, 1, 1]} Bob Hanlon On Fri, Aug 16, 2013 at 7:06 AM, Samuel Mark Young <sy81 at sussex.ac.uk>wrote: > > Hello, > > I'm looking for an easy way to remove the external parentheses from a > list. The list contains integration variables and their respective limits, > it currently looks something like this: > > {{x1,a,b},{x2,c,d},...,{xn,y,z}} > > However, the Integrate (or NIntegrate function) in Mathematica wants me to > write it like this: > > {x1,a,b},{x2,c,d},...,{xn,y,z} > i.e. The external parentheses have been removed > > I've looked around online and seen suggestions for replacing the curly > brackets "{" with a blank space " ", or using Apply (@@) but can't work out > the correct syntax. > > Thanks for any help and advice! > > Regards, > Sam > > >

**References**:**How to remove external parentheses from a list***From:*Samuel Mark Young <sy81@sussex.ac.uk>