changelog
- Wed, 22 Apr 2026 23:41:59 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 22 Apr 2026 23:41:59 -0500] rev 197
- Fix internal links in documentation
- Thu, 19 Mar 2026 18:21:40 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 19 Mar 2026 18:21:40 -0500] rev 196
- Remove apparently now unused cow_is_borrowed feature request
- Tue, 24 Feb 2026 09:44:53 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 24 Feb 2026 09:44:53 -0500] rev 195
- Add LowerExp to Float trait bounds
- Thu, 15 Jan 2026 16:12:47 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 15 Jan 2026 16:12:47 -0500] rev 194
- apply_and_differential_impl
- Mon, 08 Dec 2025 15:23:42 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 08 Dec 2025 15:23:42 -0500] rev 193
- maybe_uninit_slice is stable
- Mon, 01 Dec 2025 19:50:58 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Dec 2025 19:50:58 -0500] rev 192
- Implement Euclidean for f32 and f64
- Fri, 28 Nov 2025 14:01:14 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 28 Nov 2025 14:01:14 -0500] rev 191
- Add residual to DataTerm
- Fri, 28 Nov 2025 13:28:17 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 28 Nov 2025 13:28:17 -0500] rev 190
- Bump nalgebra version to 0.34.0
- Fri, 28 Nov 2025 11:28:01 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 28 Nov 2025 11:28:01 -0500] rev 189
- pyo3 update to 0.27
- Tue, 09 Sep 2025 08:24:27 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 09 Sep 2025 08:24:27 -0500] rev 188
- Remove Norm trait bound from BoundedLinear
- Mon, 08 Sep 2025 19:22:13 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 08 Sep 2025 19:22:13 -0500] rev 187
- Pair L2 norms and distances
- Sun, 07 Sep 2025 10:00:14 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 07 Sep 2025 10:00:14 -0500] rev 186
- StaticEuclidean Principal reference fix
- Sun, 07 Sep 2025 09:51:26 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 07 Sep 2025 09:51:26 -0500] rev 185
- StaticEuclideanOriginGenerator
- Sun, 07 Sep 2025 09:44:43 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 07 Sep 2025 09:44:43 -0500] rev 184
- SimplyAdjointable to avoid type system limitations
- Sat, 06 Sep 2025 23:29:34 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sat, 06 Sep 2025 23:29:34 -0500] rev 183
- wrap guard interface
- Fri, 05 Sep 2025 13:30:53 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 13:30:53 -0500] rev 182
- Disable Pair reference pyo3 conversions to avoid compiler bugs
- Fri, 05 Sep 2025 01:09:21 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 01:09:21 -0500] rev 181
- Simplify nalgebra trait bounds further
- Fri, 05 Sep 2025 01:02:53 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 01:02:53 -0500] rev 180
- Less DefaultAllocate trait bounds
- Fri, 05 Sep 2025 00:56:59 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 00:56:59 -0500] rev 179
- wrap
- Fri, 05 Sep 2025 00:55:10 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 00:55:10 -0500] rev 178
- More matrix instances
- Fri, 05 Sep 2025 00:48:59 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 00:48:59 -0500] rev 177
- AXPY implementation reductions
- Fri, 05 Sep 2025 00:16:08 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 05 Sep 2025 00:16:08 -0500] rev 176
- strides alt
- Wed, 03 Sep 2025 22:05:33 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 22:05:33 -0500] rev 175
- wrap
- Wed, 03 Sep 2025 21:31:13 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 21:31:13 -0500] rev 174
- nalgebra matrix distances
- Wed, 03 Sep 2025 21:03:47 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 21:03:47 -0500] rev 173
- No either
- Wed, 03 Sep 2025 20:52:21 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 20:52:21 -0500] rev 172
- nalgebra instance hacks
- Wed, 03 Sep 2025 20:19:41 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 20:19:41 -0500] rev 171
- decompose
- Wed, 03 Sep 2025 19:55:05 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 19:55:05 -0500] rev 170
- either
- Wed, 03 Sep 2025 19:37:15 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 19:37:15 -0500] rev 169
- Can only do nalgebra matrix ops for OMatrix (but ok through Instance) to avoid having to specify types
- Wed, 03 Sep 2025 17:59:24 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 17:59:24 -0500] rev 168
- No supertraits for Instance
- Wed, 03 Sep 2025 14:27:21 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 14:27:21 -0500] rev 167
- nalgebra stuff
- Wed, 03 Sep 2025 13:15:32 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 13:15:32 -0500] rev 166
- todos
- Wed, 03 Sep 2025 12:55:27 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 12:55:27 -0500] rev 165
- Copiable MatrixViews
- Wed, 03 Sep 2025 10:08:28 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 10:08:28 -0500] rev 164
- OwnedSpace -> Principal
- Wed, 03 Sep 2025 09:52:30 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 09:52:30 -0500] rev 163
- convexity etc. fubar
- Wed, 03 Sep 2025 09:16:03 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 09:16:03 -0500] rev 162
- cow_owned etc.
- Wed, 03 Sep 2025 08:40:17 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 03 Sep 2025 08:40:17 -0500] rev 161
- try
- Tue, 02 Sep 2025 15:18:30 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 02 Sep 2025 15:18:30 -0500] rev 160
- Viewable hack not needed now
- Tue, 02 Sep 2025 15:11:35 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 02 Sep 2025 15:11:35 -0500] rev 159
- nalgebra horror
- Tue, 02 Sep 2025 12:37:53 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 02 Sep 2025 12:37:53 -0500] rev 158
- fubar
- Tue, 02 Sep 2025 08:01:57 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 02 Sep 2025 08:01:57 -0500] rev 157
- matrix fubar
- Tue, 02 Sep 2025 00:09:46 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 02 Sep 2025 00:09:46 -0500] rev 156
- sketc
- Tue, 02 Sep 2025 00:05:29 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 02 Sep 2025 00:05:29 -0500] rev 155
- bazquk
- Mon, 01 Sep 2025 23:08:27 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 23:08:27 -0500] rev 154
- tune
- Mon, 01 Sep 2025 23:08:01 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 23:08:01 -0500] rev 153
- tune
- Mon, 01 Sep 2025 23:03:27 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 23:03:27 -0500] rev 152
- fubar
- Mon, 01 Sep 2025 20:55:34 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 20:55:34 -0500] rev 151
- lots of space changes
- Mon, 01 Sep 2025 13:51:03 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 13:51:03 -0500] rev 150
- fubar
- Mon, 01 Sep 2025 00:04:22 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 00:04:22 -0500] rev 149
- wrap hacks
- Mon, 01 Sep 2025 00:04:16 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 01 Sep 2025 00:04:16 -0500] rev 148
- AXPY for nalgebra matrices, not just vectors
- Sat, 30 Aug 2025 22:43:37 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sat, 30 Aug 2025 22:43:37 -0500] rev 147
- Bump pyo3
- Sat, 30 Aug 2025 22:25:28 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sat, 30 Aug 2025 22:25:28 -0500] rev 146
- wrap sketch
- Sun, 18 May 2025 23:31:48 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 18 May 2025 23:31:48 -0500] rev 145
- Dist argument order changed to reflect other changes
- Sun, 18 May 2025 23:15:50 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 18 May 2025 23:15:50 -0500] rev 144
- Basic Pair pyo3 conversions
- Sun, 18 May 2025 19:56:28 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 18 May 2025 19:56:28 -0500] rev 143
- Added rustfmt.toml
- Tue, 13 May 2025 15:13:51 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 13 May 2025 15:13:51 -0500] rev 142
- .hgignore
- Wed, 07 May 2025 11:35:17 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 07 May 2025 11:35:17 -0500] rev 141
- Add .hgignore
- Tue, 13 May 2025 08:44:41 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 13 May 2025 08:44:41 -0500] rev 140
- Generalise ZeroOp
- Tue, 13 May 2025 00:24:51 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 13 May 2025 00:24:51 -0500] rev 139
- new ZeroOp
- Mon, 12 May 2025 23:29:17 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 23:29:17 -0500] rev 138
- dual_origin
- Mon, 12 May 2025 22:48:16 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 22:48:16 -0500] rev 137
- instantiated-fubar
- Mon, 12 May 2025 21:56:42 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 21:56:42 -0500] rev 136
- instance-lifetime-fubar2
- Mon, 12 May 2025 21:36:41 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 21:36:41 -0500] rev 135
- fubar
- Mon, 12 May 2025 21:26:04 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 21:26:04 -0500] rev 134
- instance-lifetime-fubar
- Mon, 12 May 2025 20:40:14 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 20:40:14 -0500] rev 133
- Replace Instance ref_instance and decompose by eval_* for flexibility
- Mon, 12 May 2025 19:30:41 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 19:30:41 -0500] rev 132
- Make Euclidean depend on AXPY
- Mon, 12 May 2025 17:10:39 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 17:10:39 -0500] rev 131
- euclidean simplify fail
- Mon, 12 May 2025 16:28:50 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 16:28:50 -0500] rev 130
- Add more AXPY super traits
- Mon, 12 May 2025 15:42:48 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 12 May 2025 15:42:48 -0500] rev 129
- Simplify ZeroOp to SimpleZeroOp, only from X to X. Add Prox for ZeroIndicator. Move F parameter to AXPY::Field.
- Sun, 11 May 2025 02:03:45 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 11 May 2025 02:03:45 -0500] rev 128
- Switch from Cow to MyCow for DifferentiableImpl to avoid Clone trait bound
- Thu, 08 May 2025 22:53:31 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 08 May 2025 22:53:31 -0500] rev 127
- Make midpoints of p2_local_models public
- Thu, 01 May 2025 15:32:10 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 15:32:10 -0500] rev 126
- MinMaxMapping default implementations
- Thu, 01 May 2025 14:53:14 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 14:53:14 -0500] rev 125
- Allow MinMaxMappings on any domain
- Thu, 01 May 2025 13:06:58 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 13:06:58 -0500] rev 124
- Transpose loc parameters to allow f64 defaults
- Thu, 01 May 2025 12:29:18 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 12:29:18 -0500] rev 123
- numseal
- Thu, 01 May 2025 08:40:33 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 08:40:33 -0500] rev 122
- remove quadratic
- Thu, 01 May 2025 02:28:28 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 02:28:28 -0500] rev 121
- another overflow
- Thu, 01 May 2025 02:13:44 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 02:13:44 -0500] rev 120
- reduce restriction
- Thu, 01 May 2025 02:09:50 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 02:09:50 -0500] rev 119
- simplify
- Thu, 01 May 2025 01:55:57 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 01:55:57 -0500] rev 118
- restrict
- Thu, 01 May 2025 01:31:25 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 01:31:25 -0500] rev 117
- binops_mut
- Thu, 01 May 2025 01:25:27 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 01:25:27 -0500] rev 116
- binops
- Thu, 01 May 2025 01:16:13 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 01:16:13 -0500] rev 115
- ops
- Thu, 01 May 2025 01:05:00 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 01:05:00 -0500] rev 114
- impl_euclidean with fixed field
- Thu, 01 May 2025 00:08:09 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 00:08:09 -0500] rev 113
- is_zero default
- Thu, 01 May 2025 00:01:15 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 01 May 2025 00:01:15 -0500] rev 112
- Missing Norm222 traits
- Wed, 30 Apr 2025 23:57:17 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 30 Apr 2025 23:57:17 -0500] rev 111
- clone
- Wed, 30 Apr 2025 16:39:01 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 30 Apr 2025 16:39:01 -0500] rev 110
- Use DynResult for Lipschitz factors and operator norm bounds
- Wed, 30 Apr 2025 01:06:25 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 30 Apr 2025 01:06:25 -0500] rev 109
- More Normed usage
- Wed, 30 Apr 2025 00:48:56 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 30 Apr 2025 00:48:56 -0500] rev 108
- factor_of_strong_convexity
- Wed, 30 Apr 2025 00:29:16 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 30 Apr 2025 00:29:16 -0500] rev 107
- Missing restriction in Conjugable
- Wed, 30 Apr 2025 00:23:04 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Wed, 30 Apr 2025 00:23:04 -0500] rev 106
- Added missing derives
- Tue, 29 Apr 2025 07:55:18 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 29 Apr 2025 07:55:18 -0500] rev 105
- sketch
- Tue, 29 Apr 2025 00:03:12 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 29 Apr 2025 00:03:12 -0500] rev 104
- Norm222
- Mon, 28 Apr 2025 23:16:56 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 28 Apr 2025 23:16:56 -0500] rev 103
- Add generic scalar right multiplication for Pair
- Mon, 28 Apr 2025 21:32:37 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 28 Apr 2025 21:32:37 -0500] rev 102
- LipschitzDifferentiableImpl
- Mon, 28 Apr 2025 16:52:15 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 28 Apr 2025 16:52:15 -0500] rev 101
- Add some missing #derives
- Mon, 28 Apr 2025 09:08:45 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 28 Apr 2025 09:08:45 -0500] rev 100
- Remove Send + Sync + 'static requirement on NormExponent. Allow Zed to reindent norms.rs.
- Mon, 28 Apr 2025 08:26:04 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 28 Apr 2025 08:26:04 -0500] rev 99
- Quadratic Mappings; Lipschitz trait (moved from pointsource_algs).
- Sun, 27 Apr 2025 20:41:36 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 27 Apr 2025 20:41:36 -0500] rev 98
- merge stable/nightly fixes from default
- Sun, 27 Apr 2025 15:56:43 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 27 Apr 2025 15:56:43 -0500] rev 97
- MinMaxMapping trait to allow alternatives to BTFN with relevant properties.
- Sun, 27 Apr 2025 15:45:40 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 27 Apr 2025 15:45:40 -0500] rev 96
- Allow Zed to reindent btfn.rs, support.rs, aggregator.rs, and bt.rs.
- Sun, 27 Apr 2025 14:48:13 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 27 Apr 2025 14:48:13 -0500] rev 95
- Start work on 0.4.0(-dev).
- Sun, 27 Apr 2025 20:29:43 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 27 Apr 2025 20:29:43 -0500] rev 94
- Fix build with stable rust.
For optimisations, build.rs now automatically sets a nightly cfg flag,
so problems with the nightly feature are avoided. It is still used for
required for additional nightly-only features.
- Tue, 08 Apr 2025 13:30:12 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 08 Apr 2025 13:30:12 -0500] rev 93
- Let Zed auto-indent modified files
- Tue, 08 Apr 2025 13:30:08 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Tue, 08 Apr 2025 13:30:08 -0500] rev 92
- maybe_uninit_uninit_array deprecation fix.
- Fri, 14 Feb 2025 23:31:24 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Fri, 14 Feb 2025 23:31:24 -0500] rev 91
- slice_assume_init_mut deprecation workaround
- Mon, 03 Feb 2025 19:22:16 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 03 Feb 2025 19:22:16 -0500] rev 90
- merge dev to default
- Thu, 23 Jan 2025 23:38:40 +0100
- by Tuomo Valkonen <tuomov@iki.fi> [Thu, 23 Jan 2025 23:38:40 +0100] rev 89
- bump version
- Sun, 19 Jan 2025 22:33:21 +0100
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 19 Jan 2025 22:33:21 +0100] rev 88
- doc updates
- Sun, 19 Jan 2025 16:49:09 +0100
- by Tuomo Valkonen <tuomov@iki.fi> [Sun, 19 Jan 2025 16:49:09 +0100] rev 87
- LogarithmicCap verbosity option
- Mon, 06 Jan 2025 20:29:25 -0500
- by Tuomo Valkonen <tuomov@iki.fi> [Mon, 06 Jan 2025 20:29:25 -0500] rev 86
- More Serialize / Deserialize / Debug derives