Add explanation for split=100

diff --git a/lib/dictBuilder/zdict.h b/lib/dictBuilder/zdict.h
index 9357e40a603e0c0199e85a5bdef78622b003fa07..4094669d12dd05c378cf8b05b20e385ed581bae0 100644 (file)
--- a/lib/dictBuilder/zdict.h
+++ b/lib/dictBuilder/zdict.h
@@ -86,7 +86,7 @@ typedef struct {
     unsigned d;                  /* dmer size : constraint: 0 < d <= k : Reasonable range [6, 16] */
     unsigned steps;              /* Number of steps : Only used for optimization : 0 means default (32) : Higher means more parameters checked */
     unsigned nbThreads;          /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
-    double splitPoint;           /* Percentage of samples used for training: the first nbSamples * splitPoint samples will be used to training, 0 means default (1.0) */
+    double splitPoint;           /* Percentage of samples used for training: the first nbSamples * splitPoint samples will be used to training, the last nbSamples * (1 - splitPoint) samples will be used for testing, 0 means default (1.0), 1.0 when all samples are used for both training and testing */
     ZDICT_params_t zParams;
 } ZDICT_cover_params_t;
 

diff --git a/programs/zstd.1 b/programs/zstd.1
index 3e9e2942381067a3a8bfb90b2a78ffaabea2650f..9d1e45cfe7d3a8b3f2cd973ceff8b0b8b8cfe401 100644 (file)
--- a/programs/zstd.1
+++ b/programs/zstd.1
@@ -218,7 +218,8 @@ A dictionary ID is a locally unique ID that a decoder can use to verify it is us
 .
 .TP
 \fB\-\-train\-cover[=k#,d=#,steps=#,split=#]\fR
-Select parameters for the default dictionary builder algorithm named cover\. If \fId\fR is not specified, then it tries \fId\fR = 6 and \fId\fR = 8\. If \fIk\fR is not specified, then it tries \fIsteps\fR values in the range [50, 2000]\. If \fIsteps\fR is not specified, then the default value of 40 is used\. If \fIsplit\fR is not specified or \fIsplit\fR <= 0 or \fIsplit\fR > 100, then the default value of 100 is used\. Requires that \fId\fR <= \fIk\fR\.
+Select parameters for the default dictionary builder algorithm named cover\. If \fId\fR is not specified, then it tries \fId\fR = 6 and \fId\fR = 8\. If \fIk\fR is not specified, then it tries \fIsteps\fR values in the range [50, 2000]\. If \fIsteps\fR is not specified, then the default value of 40 is used\. If \fIsplit\fR is not specified or \fIsplit\fR <= 0, then the default value of 100 is used\. If \fIsplit\fR is 100, all input samples are used for both training and testing
+to find optimal _d_ and _k_ to build dictionary.Requires that \fId\fR <= \fIk\fR\.
 .
 .IP
 Selects segments of size \fIk\fR with highest score to put in the dictionary\. The score of a segment is computed by the sum of the frequencies of all the subsegments of size \fId\fR\. Generally \fId\fR should be in the range [6, 8], occasionally up to 16, but the algorithm will run faster with d <= \fI8\fR\. Good values for \fIk\fR vary widely based on the input data, but a safe range is [2 * \fId\fR, 2000]\. Supports multithreading if \fBzstd\fR is compiled with threading support\.

diff --git a/programs/zstd.1.md b/programs/zstd.1.md
index df6f777df18bca4858d25e4a6bb0492c5103a4f9..7e21073d7d52aba43ab8edc3c9fdf6d0f3cc3915 100644 (file)
--- a/programs/zstd.1.md
+++ b/programs/zstd.1.md
@@ -228,7 +228,7 @@ Compression of small files similar to the sample set will be greatly improved.
     If _d_ is not specified, then it tries _d_ = 6 and _d_ = 8.
     If _k_ is not specified, then it tries _steps_ values in the range [50, 2000].
     If _steps_ is not specified, then the default value of 40 is used.
-    If _split_ is not specified or split <= 0 or split > 100, then the default value of 100 is used.
+    If _split_ is not specified or split <= 0, then the default value of 100 is used.
     Requires that _d_ <= _k_.
 
     Selects segments of size _k_ with highest score to put in the dictionary.
@@ -238,6 +238,8 @@ Compression of small files similar to the sample set will be greatly improved.
     algorithm will run faster with d <= _8_.
     Good values for _k_ vary widely based on the input data, but a safe range is
     [2 * _d_, 2000].
+    If _split_ is 100, all input samples are used for both training and testing
+    to find optimal _d_ and _k_ to build dictionary.
     Supports multithreading if `zstd` is compiled with threading support.
 
     Examples: